Xray XB8 series soft, ribbed shock membranes
Coming from Xray and made for the XB8 series of buggies, trucks and cars are soft, ribbed shock absorber volume compensators. The membranes are of a softer material than stock which results in reduced shock rebound, making them ideal for bumpy or high speed tracks. Internal ribbings ensure they maintain their shape even when the going gets tough as does the heavy duty rubber material. The membranes come in sets of four and they fit the XB8, XT8 and GTX8 kits.
Source: Xray [teamxray.com]