This is the Tekno RC Shock Pistons CNC, 2x1.8, flat/flat, 13mm.

With these optional pistons, it is now easier than ever to fine-tune suspension characteristics based on your needs. Made from precision machined self-lubricating delrin, these CNC pistons have two large 1.8mm holes and four small relief holes. The TKR6732 Shock Pistons are for use in the Tekno RC EB410 1/10th Scale 4wd Buggy.

*NOTE: Shock shaft and screw sold separately.