Shimano R451 Dual Pivot Front Brake Caliper Features Good value 57 mm drop front calliper brake Super SLR dual pivot design keeps operating friction to a minimum, improving braking performance Must be used in conjunction with ST-4600, ST-4603, ST-5700, ST-5703, ST-6700 or ST-7900 STIsfor correct leverage ratio Enhanced brake arch proportions give a quicker linear response and increased power 57 mm drop Lightweight aluminium calliper design with tough anodised finish Toe-in adjustable brake shoes for perfect pad alignment Durable quick release for fast and easy wheel removal Comes with 10.5 / 12.5 / 18 / and 27 mm sunken nut