VEX Robotics Sprocket and Chain Kit Length: 2 preassembled chains of 163 links each, total of 48 in. Master Link: 326 total, Center Hole Size: 0.125 in. square Chain Material: Plastic, Chain Size: 0.25 in. wide Chain and Sprocket Pitch: 0.1475 in. Sprocket OD: 10t = .526 in. | 15t = .75 in. | 24t = 1.18 in. | 40t = 1.93 in. | 48t = 2.3 in.