Zen Racing front end suspension balls w/O-ring
Designed to improve the front end damping on LMP or RXGT12 kits are 6mm front suspension balls from Zen Racing. The O-rings inside, held by a slot, increase 1/8th king pin dampening and they hold the chosen dampening fluid against the king pin for a more consistent feel.
Source: Zen Racing [zen-racing.co.uk]