Front Hydraulic Brake Set (4pcs Set). Mini pocket bike hydraulic brake caliper w disk 33cc 43cc 47cc 49cc x1 x2 x6 x7 fits 33cc 43cc 47cc 49cc super bikes & stand up scooters. Fits the following model of mini bikes & Many More not listed here. Brake Disk Mounting Holes are about 27mm apart.