ST40/38-44/32

Rear, 4-piston, balance-optimized big brake kit for BMW E60/E61 5-Series (535i, 545i, 550i) and E63/E64 6-Series (645Ci, 650i). This kit is discontinued by StopTech/Centric. It includes Drilled or Slotted 2pc Aerorotors (355mm), 4-piston ST40 forged calipers, forged caliper brackets, Sport pads (309 Sport), and DOT-compliant stainless steel brake lines. Aerorotors feature patented directional vaning for enhanced cooling. ST40 calipers are forged aluminum with center bridge reinforcement and vehicle-specific piston sizes for optimal brake balance. The 309 Sport pads offer strong initial bite and consistent performance for aggressive street, autocross, or light track use. 18" wheels are required.