T-Works spring steel spool cups
T-Works have spring steel spool cups for a range of 1/10th touring cars available. They are made from the same hardened steel material as their tool tips and the parts are available for the Xray T2, T3 and T4 line, the CSO One, Spec-R R1 and S1 as well as the Team C TC10 and the VBC D06 and D07 cars.
Source: T-Works [rc-tworks.com]