Team Associated 13mm Front Shock Springs, Gray ASS91941
Team Associated 13mm Front Shock Spring. These replacement springs are intended for the Team Associated B6.4D, however, it will also work with the Team Associated B6.4 as a tuning option. Package includes two springs. 
Effects of Shock Spring Changes Shock Spring Characteristic SofterIncreased Chassis Roll
Increased Traction
Better in Bumpy Conditions
More Likely to Bottom Out
 StifferDecreased Chassis Roll
Decreased Traction
Increased Responsiveness
This part fits the following vehicles:
RC10B6.4
RC10B6.4D
RC10B74.2
RC10B74.2D