Find Your C180™ Rocket Size
Enter your rider's two knee measurements and we'll match them to a C180™ Rocket size: Small, Large or X-Large. All measurements in inches. Tap the guide to enlarge.
C180™ Rocket Size Finder
Enter both measurements below. Use inches only.
How to Measure
Össur sizes the C180™ Rocket with two measurements. Measure with your rider standing, weight on the leg, then enter them in the size finder above.
Knee Width (Caliper)
Measure the width of the knee from side to side at the joint line, in a standard standing, weight-bearing position.
Circumference
Measure around the leg just below the bottom (distal) edge of the kneecap.
C180™ Rocket Size Chart
All measurements in inches, with centimeters in brackets. The C180™ Rocket does not come in a Medium size: choose Small, Large or X-Large.
| Size | Knee Width | Circumference | Motocross Kit |
|---|---|---|---|
| Small (S) | 3" – 3.5" (7.6 – 8.9 cm) | 9.5" – 11" (24.1 – 27.9 cm) | Small / Large kit |
| Large (L) | 3.3" – 3.75" (8.3 – 9.5 cm) | 10" – 12" (26 – 29.8 cm) | Small / Large kit |
| X-Large (XL) | 3.5" – 4" (8.9 – 10.2 cm) | 11" – 12.5" (27.9 – 32.1 cm) | X-Large kit |
Small (S)
- Knee Width
- 3" – 3.5" (7.6 – 8.9 cm)
- Circumference
- 9.5" – 11" (24.1 – 27.9 cm)
- Motocross Kit
- Small / Large kit
Large (L)
- Knee Width
- 3.3" – 3.75" (8.3 – 9.5 cm)
- Circumference
- 10" – 12" (26 – 29.8 cm)
- Motocross Kit
- Small / Large kit
X-Large (XL)
- Knee Width
- 3.5" – 4" (8.9 – 10.2 cm)
- Circumference
- 11" – 12.5" (27.9 – 32.1 cm)
- Motocross Kit
- X-Large kit
Between Two Sizes?
The size ranges overlap (for example, a 3.4" knee width falls in both Small and Large), so if the knee width fits two sizes, use the circumference just below the kneecap to decide. Measurements still point to different sizes? Contact The CTI Shop before ordering.
Left or right?
Each C180™ Rocket brace is side-specific: choose Left for the left knee or Right for the right knee. The Pair Bundle – Motocross Edition includes 1 Left + 1 Right brace in the same size. Need a different size for each knee? Contact us before ordering.
Which Motocross Kit fits?
- Small / Large kit: fits Small and Large C180™ Rocket braces.
- X-Large kit: fits X-Large C180™ Rocket braces.
- Each C180™ Rocket Motocross Kit includes 1 knee brace undersleeve, 1 set of gear guards and 1 patella cup. The brace is not included.
Fine-tune the width at the knee
The brace comes with 6 mm (1/4") condyle pads. Per the Össur instructions, they can be replaced with thinner 3 mm (1/8") or 1.5 mm (1/16") pads, or a shim can be added behind the 6 mm pad for a snugger fit. All straps adjust in length.
Extension stops: the brace ships with a 0° extension stop installed, plus 5–10°, 10–20°, 20–30° and 30–40° stops. They are not a sizing tool. Always use the same stop on both hinges, and follow the Instructions for Use included with the brace.
Found Your C180™ Rocket Size?
Choose the size, then select Left or Right. If the measurements don't clearly match one size, contact us before ordering.
Shop C180™ Rocket
