Wheel Bearing spacers fit between inner and outer bearings. Preventing over tightening and consistently setting bearing preload while reducing bearing drag. US Patent No. 6,312,162.;
Responsive image

Allstar Performance ALL72320-4 Wheel Bearing Spacer - Steel - Wide-5 Hubs - Set of 4

Wheel Bearing spacers fit between inner and outer bearings. Preventing over tightening and consistently setting bearing preload while reducing bearing drag. US Patent No. 6,312,162.;