1. Material: aluminum alloy + ceramic bearing
2. Strong wear resistance, skeletonized for weight reduction
3. Sturdy and durable, not easy to deformation

SDL-11
1. Inner diameter: 6 mm (fitted with reducer sleeve 5/4 mm)
2. Number of teeth: 11 teeth
3. Size: diameter 41 mm, thickness about 8.5 mm
4. Weight: 7.2g for single guide wheel, 12g for complete set

SDL-13
1. Inner diameter: 6 mm (with reducer set 5/4 mm)
2. Number of teeth: 13 teeth
3. Size: diameter 51 mm, thickness about 8.5 mm
4. Weight: 10.2g for single guide wheel, 15g for complete set

SDL-17
1. Inner diameter: 6 mm (with reducer bushing 5/4 mm)
2. Number of teeth: 17 teeth
3. Size: diameter 67 mm, thickness about 8.5 mm
4. Weight: single guide wheel 15.2 grams, the whole set of 20 grams