Knuckle™
A results-focused training tool built for stretch, progression, and capacity.
Choose Your Size
22
Max Diameter2.2"5.6 cm
Max Circumference6.9"17.5 cm
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25
Max Diameter2.5"6.4 cm
Max Circumference7.9"20.1 cm
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28
Max Diameter2.8"7.1 cm
Max Circumference8.7"22.1 cm
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30
Max Diameter3.0"7.6 cm
Max Circumference9.5"24.1 cm
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32
Max Diameter3.2"8.1 cm
Max Circumference10.6"26.9 cm
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35
Max Diameter3.5"8.9 cm
Max Circumference11.0"27.9 cm
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38
Max Diameter3.8"9.7 cm
Max Circumference12.0"30.5 cm
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40
Max Diameter4.0"10.2 cm
Max Circumference12.6"32.0 cm
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42
Max Diameter4.2"10.7 cm
Max Circumference13.3"33.8 cm
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44
Max Diameter4.4"11.2 cm
Max Circumference14.1"35.8 cm
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46
Max Diameter4.6"11.7 cm
Max Circumference14.6"37.1 cm
View Size →Why Knuckle™?
Multi-Stage Design
Every Knuckle features a tapered profile that offers several usable diameters within one design. The upper portion of a larger Knuckle can often match the maximum diameter of a smaller size, making every step more versatile.
Made For Fisting
Knuckle imitates the shape of a fist. Whether you're looking to take your first fist or your first double, there's a Knuckle that will help you create the muscle memory required.
Why The Numbers Matter
The number in each Knuckle name represents its maximum diameter. For example, Knuckle 30 reaches 3.0 inches in diameter, while Knuckle 46 reaches 4.6 inches. This makes it easy to compare sizes and choose the right next step.
Handcrafted in Canada
Every Knuckle is handcrafted in small batches using premium platinum-cure silicone and built to deliver the consistency, durability, and quality Friendly Toys is known for.
Compare Sizes
Compare every Knuckle™ size at a glance.
Swipe to compare sizes →
| Size | Max Diameter | Max Circumference | Neck Circumference | Insertable Length |
|---|---|---|---|---|
| 22 | 2.2"5.6 cm | 6.9"17.5 cm | 4.5"11.4 cm | 6.0"15.2 cm |
| 25 | 2.5"6.4 cm | 7.9"20.1 cm | 4.5"11.4 cm | 6.5"16.5 cm |
| 28 | 2.8"7.1 cm | 8.7"22.1 cm | 6.0"15.2 cm | 6.5"16.5 cm |
| 30 | 3.0"7.6 cm | 9.5"24.1 cm | 6.4"16.3 cm | 7.0"17.8 cm |
| 32 | 3.2"8.1 cm | 10.6"26.9 cm | 6.7"17.0 cm | 7.2"18.3 cm |
| 35 | 3.5"8.9 cm | 11.0"27.9 cm | 7.3"18.5 cm | 7.5"19.1 cm |
| 38 | 3.8"9.7 cm | 12.0"30.5 cm | 8.4"21.3 cm | 8.0"20.3 cm |
| 40 | 4.0"10.2 cm | 12.6"32.0 cm | 8.9"22.6 cm | 8.0"20.3 cm |
| 42 | 4.2"10.7 cm | 13.3"33.8 cm | 10.3"26.2 cm | 8.5"21.6 cm |
| 44 | 4.4"11.2 cm | 14.1"35.8 cm | 10.5"26.7 cm | 9.0"22.9 cm |
| 46 | 4.6"11.7 cm | 14.6"37.1 cm | 10.5"26.7 cm | 9.0"22.9 cm |