DMM Ultra O Durolock
Right of Return
Right of Return
You always have a 14-day right of return at Arboristbutiken.
Shipping & Delivery
Shipping & Delivery
Free shipping on all orders over 2000 SEK. Arboristbutiken uses DHL, and orders placed before 12:00 are shipped the same day. Delivery time within Sweden is usually 1-2 working days.
Size Guide
Official measurement charts for climbing harnesses, chainsaw protective trousers, shoes, gloves, and jackets. All measurements are in centimeters unless otherwise specified.
| Size | Waist Belt (cm) | Leg Loop (cm) | Body Height (cm) | Weight (g) |
|---|---|---|---|---|
| 0 | 65–80 | 44–59 | 160–180 | 1 935 |
| 1 | 70–93 | 47–62 | 165–185 | 1 975 |
| 2 | 83–120 | 50–65 | 175–200 | 2 075 |
Applies to Petzl AVAO & SEQUOIA. Measurements refer to body measurements, not clothing measurements.
| Size | Hip/Waist (cm) | Thigh/Leg Loop (cm) | Max User Weight |
|---|---|---|---|
| S | 69–86 | 38–57 | 150 kg |
| M | 80–105 | 42–72 | |
| L | 92–129 | 48–87 |
Applies to TreeMotion Pro X. Unisex ergonomic design. Max 150 kg including equipment.
| Size | Waist Measurement (cm) | Leg Loop (cm) |
|---|---|---|
| S (Small) | 65–83 | 44–59 |
| M (Medium) | 75–102 | 47–63 |
| L (Large) | 88–123 | 51–73 |
Applies to Kinisi MAX, PRO and KEY. Side rings should be centered on the hip or slightly forward. Max 150 kg.
| Size | Waist (cm) | Regular Leg Length (cm) |
|---|---|---|
| XS | 80 | 80 |
| S | 86 | 81–83 |
| M | 90 | 85–86 |
| L | 94 | 88–89 |
| XL | 98 | 86 |
| 2XL | 102 | 86 |
Class 1 chainsaw protection, Type A, 20 m/s. Slim design with 4-way stretch.
| Size | Waist Measurement (cm) | Leg Loop (cm) |
|---|---|---|
| XS/S | 60–80 | 40–55 |
| M/L | 75–100 | 48–65 |
| XL/XXL | 90–120 | 55–75 |
Check the manufacturer's current datasheet for model-specific measurements. General guidelines are shown above.
| Size | Waist Measurement (cm) | Leg Loop (cm) |
|---|---|---|
| S | 62–80 | 40–56 |
| M | 76–98 | 48–64 |
| L | 88–118 | 53–72 |
Check the manufacturer's current datasheet for model-specific measurements.
| Size | Waist Measurement (cm) | Leg Loop (cm) |
|---|---|---|
| S/M | 66–96 | 41–61 |
| L/XL | 86–121 | 51–76 |
Check the manufacturer's current datasheet for model-specific measurements.
| Size | Waist (cm) | Regular Leg Length (cm) | Long Leg Length (cm) | Short Leg Length (cm) |
|---|---|---|---|---|
| 2XS | 74 | 80 | 87 | 75 |
| XS | 80 | 80 | 87 | 75 |
| S | 86 | 80 | 87 | 75 |
| M | 92 | 80 | 87 | 75 |
| L | 98 | 80 | 87 | 75 |
| XL | 104 | 80 | 87 | 75 |
| 2XL | 110 | 80 | 87 | 75 |
| 3XL | 116 | 80 | 87 | 75 |
| 4XL | 122 | 80 | 87 | 75 |
Body measurements. Choose leg length (regular/long/short) separately.
| EU Size | Waist (cm) | Regular Leg Length (cm) | Long Leg Length (cm) |
|---|---|---|---|
| 42 | 74 | 80 | 88 |
| 44 | 78 | 80 | 88 |
| 46 | 82 | 82 | 90 |
| 48 | 86 | 82 | 90 |
| 50 | 90 | 82 | 90 |
| 52 | 94 | 82 | 90 |
| 54 | 98 | 83 | 90 |
| 56 | 102 | 83 | 90 |
| 58 | 108 | 83 | 90 |
| 60 | 114 | 83 | 90 |
Waist measured at the top edge of the trousers (Bundweite). Stretch-Zone provides an elastic fit.
| Size | Waist (cm) | Short Leg Length (cm) | Regular Leg Length (cm) | Long Leg Length (cm) |
|---|---|---|---|---|
| XS | 63–71 | – | 79 | – |
| S | 71–87 | 74 | 79 | 84 |
| M | 81–89 | 74 | 79 | 84 |
| L | 89–97 | 74 | 79 | 84 |
| XL | 97–107 | 74 | 79 | 84 |
| XXL | 107–114 | 74 | 79 | 84 |
| 3XL | 114–122 | – | 79 | – |
| 4XL | 122–129 | – | 79 | – |
| 5XL | 129–137 | – | 79 | – |
Leg length = inseam (crotch to ankle bone). BreatheFlex Pro has a slimmer fit in the thighs and legs than standard Breatheflex.
| Size | Waist (cm) |
|---|---|
| XS | 66–74 |
| S | 74–82 |
| M | 82–90 |
| L | 90–98 |
| XL | 98–106 |
| XXL | 106–117 |
| XXXL | 117–129 |
| XXXXL | 129–141 |
Body measurements. Leg length varies per model – see product datasheet. If size differs, custom manufacturing can be ordered.
| Size | Waist (cm) | Leg Length (cm) |
|---|---|---|
| XS | 80 | 80 |
| S | 86 | 81–83 |
| M | 90 | 85–86 |
| L | 94 | 88–89 |
| XL | 98 | 86 |
| 2XL | 102 | 86 |
Body measurements. 4-way stretch material.
| Size | Waist (cm) | Leg Length (cm) |
|---|---|---|
| S | 72–80 | 78 |
| M | 80–88 | 80 |
| L | 88–96 | 82 |
| XL | 96–106 | 82 |
| XXL | 106–116 | 82 |
Check the manufacturer's current datasheet for model-specific measurements.
| Size | Waist (cm) | Leg length (cm) |
|---|---|---|
| S | 74–84 | 80 |
| M | 84–94 | 82 |
| L | 94–104 | 82 |
| XL | 104–114 | 82 |
| XXL | 114–124 | 82 |
Check the manufacturer's current data sheet for model-specific measurements.
| EU | UK | US | Foot Length (cm) | Foot Width (cm) |
|---|---|---|---|---|
| 36 | 3 | 4 | 24.3 | 8.4 |
| 37 | 4 | 5 | 25.0 | 8.6 |
| 38 | 5 | 6 | 25.6 | 8.7 |
| 39 | 6 | 7 | 26.3 | 8.9 |
| 40 | 6.5 | 7.5 | 27.0 | 9.0 |
| 41 | 7 | 8 | 27.6 | 9.2 |
| 42 | 8 | 9 | 28.3 | 9.3 |
| 43 | 9 | 10 | 29.0 | 9.5 |
| 44 | 10 | 11 | 29.6 | 9.6 |
| 45 | 10.5 | 11.5 | 30.3 | 9.8 |
| 46 | 11 | 12 | 31.0 | 9.9 |
| 47 | 12 | 13 | 31.6 | 10.1 |
| 48 | 13 | 14 | 32.3 | 10.2 |
| 49 | 14 | 15 | 33.0 | 10.4 |
Foot length: measure with even weight distribution, heel to longest toe. Choose a larger size if you are in between.
| EU | UK | US | Foot Length (cm) | Mondo Point (cm) |
|---|---|---|---|---|
| 38 | 5 | 6 | 22.0 | 24.0 |
| 38.5 | 5.5 | 6.5 | 22.5 | 24.5 |
| 39 | 6 | 7 | 23.0 | 25.0 |
| 40 | 6.5 | 7.5 | 23.5 | 25.5 |
| 40.5 | 7 | 8 | 24.0 | 26.0 |
| 41 | 7.5 | 8.5 | 24.5 | 26.5 |
| 42 | 8 | 9 | 25.0 | 27.0 |
| 42.5 | 8.5 | 9.5 | 25.5 | 27.5 |
| 43 | 9 | 10 | 26.0 | 28.0 |
| 44 | 9.5 | 10.5 | 26.5 | 28.5 |
| 44.5 | 10 | 11 | 27.0 | 29.0 |
| 45 | 10.5 | 11.5 | 27.5 | 29.5 |
| 46 | 11 | 12 | 28.0 | 30.0 |
| 46.5 | 11.5 | 12.5 | 28.5 | 30.5 |
| 47 | 12 | 13 | 29.0 | 31.0 |
| 47.5 | 12.5 | 13.5 | 29.5 | 31.5 |
| 48 | 13 | 14 | 30.0 | 32.0 |
EU size may run half a size small – consider sizing up. Mondo Point = foot length + approx. 2 cm toe room.
| EU | Foot Length (cm) |
|---|---|
| 37 | 22.9 |
| 38 | 23.5 |
| 39 | 24.2 |
| 39.5 | 24.7 |
| 40 | 24.9 |
| 40.5 | 25.1 |
| 41 | 25.5 |
| 42 | 26.1 |
| 42.5 | 26.4 |
| 43 | 26.7 |
| 44 | 27.4 |
| 44.5 | 27.8 |
| 45 | 28.3 |
| 45.5 | 28.8 |
| 46 | 29.3 |
| 47 | 29.7 |
| 48 | 30.2 |
| 49 | 30.8 |
ZBPK last: good heel grip, generous toe box. May fit half a size smaller than everyday shoes. Measure foot with sock on.
| EU | Foot Length (cm) |
|---|---|
| 38 | 24.0 |
| 39 | 24.7 |
| 40 | 25.3 |
| 41 | 26.0 |
| 42 | 26.7 |
| 43 | 27.3 |
| 44 | 28.0 |
| 45 | 28.7 |
| 46 | 29.3 |
| 47 | 30.0 |
Standard EU → foot length conversion. Check manufacturer's data sheet for exact fit.
| Hand Size | Label | Hand Circumference (cm) | Hand Length (cm) |
|---|---|---|---|
| 6 | XS/S | 15.2 | 16.0 |
| 7 | S | 17.8 | 17.1 |
| 8 | M | 20.3 | 18.2 |
| 9 | L | 22.9 | 19.2 |
| 10 | XL | 25.4 | 20.4 |
| 11 | XXL | 27.9 | 21.5 |
| 12 | 3XL | 30.4 | >21.5 |
According to EN ISO 21420:2020. Hand size = number designation from the standard. Sizes 7–12 most commonly available.
| Palm Width (cm) | Size |
|---|---|
| 7 | S |
| 8 | M |
| 9 | L |
| 10 | XL |
| 11 | XXL |
| 12 | 3XL |
Measure the palm width flat with a ruler or tape measure. Size up for a looser fit. StretchFlex provides an elastic, finger-agile fit.
| Size | Hand Circumference (cm) |
|---|---|
| S | 17–19 |
| M | 19–21 |
| L | 21–23 |
| XL | 23–25 |
| XXL | 25–27 |
Measure circumference around the widest part of your hand (knuckles). Check the product data sheet for model-specific measurements.
| Size | Hand Circumference (cm) |
|---|---|
| 7 (S) | 17–19 |
| 8 (M) | 19–21 |
| 9 (L) | 21–23 |
| 10 (XL) | 23–25 |
| 11 (XXL) | 25–27 |
Guide Gloves use European hand sizes. Check the manufacturer's data sheet.
| Size | Hand Circumference (cm) |
|---|---|
| S | 17–19 |
| M | 19–21 |
| L | 21–23 |
| XL | 23–25 |
| XXL | 25–27 |
Check the manufacturer's data sheet for model-specific measurements.
| Size | Hand Circumference (cm) |
|---|---|
| S | 17–19 |
| M | 19–21 |
| L | 21–23 |
| XL | 23–25 |
Check the manufacturer's data sheet for model-specific measurements.
| Size | Chest (cm) | Waist (cm) | Body Length (cm) |
|---|---|---|---|
| XS | 84–89 | 70–75 | 166–171 |
| S | 90–95 | 76–81 | 172–177 |
| M | 96–101 | 82–87 | 178–183 |
| L | 102–107 | 88–93 | 184–189 |
| XL | 108–113 | 94–99 | 184–189 |
| XXL | 114–121 | 100–109 | 184–189 |
| 3XL | 122–129 | 110–117 | 184–189 |
Body measurements. Check the product page for specific model size information.
| Size | Chest (cm) | Waist (cm) |
|---|---|---|
| XS | 82–86 | 72–76 |
| S | 86–90 | 76–80 |
| M | 90–94 | 80–84 |
| L | 94–98 | 84–88 |
| XL | 98–104 | 88–94 |
| XXL | 104–110 | 94–100 |
| 3XL | 110–116 | 100–106 |
| 4XL | 116–122 | 106–112 |
Body measurements. Check the manufacturer's data sheet for model-specific measurements.
| Size | Chest (cm) | Waist (cm) |
|---|---|---|
| XS | 80–88 | 68–76 |
| S | 88–96 | 76–84 |
| M | 96–104 | 84–92 |
| L | 104–112 | 92–100 |
| XL | 112–122 | 100–110 |
| XXL | 122–132 | 110–120 |
| XXXL | 132–142 | 120–130 |
Body measurements. Check the product data sheet for model-specific measurements.
| Size | Chest (cm) | Waist (cm) |
|---|---|---|
| S | 88–96 | 76–84 |
| M | 96–104 | 84–92 |
| L | 104–112 | 92–100 |
| XL | 112–120 | 100–108 |
| XXL | 120–128 | 108–116 |
| 3XL | 128–136 | 116–124 |
Check the manufacturer's current data sheet for model-specific measurements.
Description
Description
The DMM Ultra O Durolock is an ultralight and extremely strong carabiner with a patented auto-locking **Durolock** gate that requires four separate movements to open. It offers maximum safety in complex rigging systems, arborist work and work-at-height operations.
The Ultra O range from DMM is one of the most popular carabiners worldwide thanks to its high strength-to-weight ratio, ergonomic feel and ability to keep system components in perfect alignment. The deep, symmetrical oval shape (**O-shape**) lets slings, ropes, blocks and other carabiners centre naturally under load, while also allowing easy stacking of components on both sides. This makes it ideal for arborists in both basic and advanced systems, such as with triple-attachment pulleys.
The Durolock system is DMM's most secure auto-lock: it requires four distinct movements to open the gate, minimising the risk of accidental opening in dynamic environments with moving ropes. The gate is still easy to operate one-handed. Made in Wales from hot-forged and heat-treated aluminium with I-beam construction for optimal strength and low weight. The Keylock nose prevents snagging on ropes and harnesses.
Features
- Durolock auto-lock: Four-step opening mechanism for the highest safety against accidental opening[1][4].
- Oval symmetrical basket: Provides natural centring of blocks, ropes and harnesses for stable loading[2][3].
- I-beam design: Maximum strength-to-weight ratio with ultralight construction[3].
- Clean nose Keylock: Snag-free connection with no risk of catching on ropes or equipment[3].
- Ergonomic: Feels good in the hand and easy to use in complex rigging[1].
- Two-finger grip: Comfortable handling even with gloves[1].
- Corrosion-protected: Anodised to BS12373-2001 Class 10E1[3].
Technical specifications
- Colour: Titanium/Purple
- MBS Major Axis: 25 kN
- MBS Minor Axis: 12 kN
- MBS Gate Open: 7 kN
- Gate Opening: 19 mm
- Dimensions: 63 x 109 mm
- Weight: 74 g
- Material: Aluminium, hot-forged
- Certification: EN 362:2004 B, EN 12275:2013 H
- Part number: A324
- Country of manufacture: United Kingdom (Wales)
Perfect for arborists, rope technicians and climbers who require reliable performance in demanding environments.

