Brembo GT 4 Piston Rear Big Brake Kit - 345x28mm 2-Piece RotorGT M4 Brake Kit For you who are passionate about track days, the GT M4 kit has been designed and specifically tested to ensure exceptional rigidity, reduced deformation, a sporty look, and superior performance. Suitable for both road use and the most demanding days on the track. The caliper is machined from a single billet of aluminum that has been cast in Brembo's foundry. This ensures outstanding rigidity and minimized deformation. Moreover, the