Product name: Brake lever/shift handle/brake lever Model: 51-7/8, suitable for front 3 teeth, rear 7/8 flywheels, 21/24-speed positioning transmission system suitable He: Mountain vehicle/urban leisure car/folding car/straight road car Specifications: 22.2mm caliber (21-23mm can be available) Note: This product is available in two types: 51-7 (21 speed)/EF51-8 speed (24 speed) Purchase instructions Company introduction