This is a set of two optional XRAY 13x19x4mm High-Speed Rubber/Steel Sealed Ball-Bearings, and are intended for use with the XRAY XB808, and XB808 09 Spec 1/8 buggies. These new high-speed ball-bearings are sealed with a rubber seal on one side and a steel seal from other side.
These ball-bearings have more (and larger) balls inside the cage than the stock ball-bearings, making them much more resilient under loads. The side covers are easy to remove for quick and comfortable servicing.
These ultra-high precision ball bearings are designed to withstand all extremes at the track under racing conditions or even just fun racing. These are a "must have" item!