This is the Traxxas 20 Tooth Steel Replacement Clutch Bell. This clutch bell attaches to the adapter unit on the crankshaft, makes contact with the clutch shoes and meshes with the main gear. FEATURES: Fits all Traxxas 1/10th scale nitro vehicles. Replaces worn or damaged clutch bells. Constructed of hardened steel. INCLUDES: One Traxxas 20 Tooth Steel Replacement Clutch Bell. Two 5mm x 11mm 0.5mm fiber washers. Two 5mm E-clips.