These washers install onto the splined shaft of the drivershaft, between the outer CV joint and wheel bearing / hub, and assist in pushing the driveshafts back into the gearbox when your car is lowered.
Price is for two washers, one for each side.
Fitting requires removing the driveshaft from the hub. The chamfered side faces inwards, with the flat side against the hub bearing. These are designed for the OEM driveshaft.