This brake, suitable for the most market models, strong braking force, do not hurt the disc. It is a fine choice for cycling enthusiasts. Features: Dual piston driving principle, drive friction disc on both sides at the same time, brake disc automatically return to position, equal force on both sides, synchronous friction, stable brake, strong braking force. Three-dimensional cylinder design, vertical cylinder can provide a larger piston in a shorter distance, a gentle pinch can easily brake. Resin to make the disc, do not hurt the disc, further improve the braking effect. Practical aluminum alloy material, quick brake, timely reset. Three-finger brake handle for easy operation of the brake. Specifications: A column: 75mm B column: 51mm Material: aluminum alloy Type1: a pair of black oil brake (front and rear) Item weight: 630g / 1.4lb Package weight: 650g / 1.4lb Type2: a pair of black oil brake (front and rear) + a pair of disc brakes Item weight: 830g / 1.8lb Package weight: 850g / 1.9lb Type3: single black oil brake (right front) Item weight: 300g / 0.7lb Package weight: 320g / 0.7lb Type4: single black oil brake (left rear) Item weight: 330g / 0.7lb Package weight: 350g / 0.8lb Type5: single black oil brake (right front) + single disc brake Item weight: 400g / 0.9lb Package weight: 420g / 0.9lb Type6: black oil brake (left rear) + single disc brake Item weight: 430g / 0.9lb Package weight: 450g / 1.0lb Package size: 250 * 200 * 50mm / 9.8 * 7.9 * 2.0in Packing List: Type1: 1 * Pair Of Black Oil Brake (front and rear) Type2: 1 * Pair Of Black Oil Brake (front and rear) 1 * Pair Of Disc Brakes Type3: 1 * Black Oil Brake (right front) Type4: 1 * Black Oil Brake (left rear) Type5: 1 * Black Oil Brake (right front) 1 * Disc Brake Type6: 1 * Black Oil Brake (left rear) 1 * Disc Brake