This is a replacement front bearing for the following O.S. engines - / .30 ROTARY(WANKEL) / .21 RX-R 1/8 scale on-road gas engine / .21 RX-B 1/8 scale off-road buggy engine / / FEATURES: Stainless steel construction / Shielded on one side / / INCLUDES: One front bearing / / SPECS: outside diameter - 19mm / inside diameter - 7mm / width - 6mm / btm 06/07/94