Tamiya AO-1026 Rubber Rings for 13-12mm Rollers (6 pcs.)(94812)

Replacement rubber O-rings for Tamiya's GP.418 Rubber-Ringed Two-Stage Aluminum Rollers (13-12mm). The rings sit in the groove of the two-stage roller to add grip and cushioning against the course fence; like any rubber part they harden and wear with use, so Tamiya sells them separately as a maintenance pack rather than requiring a whole new roller set.

The "13-12mm" in the roller's name describes its two-stage design: a 13mm-diameter stage and a smaller 12mm-diameter stage cast onto the same aluminium body, each taking its own rubber ring. The step between the two diameters is what lets the roller both guide the car along a straight fence and help it shed speed gradually rather than snapping to a stop if it clips a corner. Because the rubber compound is what actually contacts the fence, it's the part of the roller that degrades fastest — going hard and losing grip long before the aluminium body itself wears out — so restocking rings rather than replacing the whole roller is the normal maintenance path.

• Contents: 6x rubber rings
• Fits: GP.418 Two-Stage Aluminum Rollers (13-12mm) and any Mini 4WD fitted with them