This Sale is for 1 Left or Right Rear Caliper Brake Pad Anti-Rattle / Retaining Spring for Select 2000 - 2014 CL, E, GL, ML, R, Sand SL Models, 000 421 85 91
This is the spring that holds the brake pad to the floating caliper, and is used one per side of the caliper / car.
This is made in Germany by Ate, the OEM supplier to Mercedes for this part.
This OEM Ate spring will fit select models of the 2000 thru 2014 CL, E, GL, ML, R, S and SL models so PLEASE see the fitment application table to confirm.