MTEC Brakes CG29 Copper Grease helps prevent brake squeal and protects metal against corrosion. It contains elements that inhibit oxidation and corrosion of metal parts, it will also protect against seizure of metal parts. MTEC Brakes CG29 Copper Grease should be used between the brake pad backing plates and caliper piston heads and contact points. Do not apply to friction material surfaces such as brake pads and discs.