Features: 1. Braking System:Hydraulic Disc Brake (Hydraulic Brake Pad) 2. Rotors Size: 160mm Note: Please do not remove the yellow pad before installation, and pinch the brake lever, otherwise it will cause oil leakage or scrap the oil disc 3. Model Number:Disc Brake Calipers 4. Dual Piston Brake Type: Lining Pulled Hydraulic Disc Brake Suitable for mountain E-Bike,bikes, road bikes and folding bikes 5. Weight:Front 199.6g,Rear:204.8g Package List: Choice 1: 1 x  Hydraulic Disc Brake Caliper ( Front or Rear Optional) Choice 2: 1 pair x Hydraulic Disc Brake Caliper ( Front and Rear)