This is a pin clip kit for your Brembo calipers. Make sure to order the correct one for your application. 

Front 6 Piston: work for all GM 6 piston Brembo calipers.

Front 4 Piston: work for 2004-07 CTS-V, standard ATS Brembo fronts, 2010-15 Camaro SS, 2008 G8 GXP fronts, 2014+ Chevy SS fronts, etc.

Rear 4 Piston: work for all rears except ZR1 and Z28 or carbon rotor setups.