What is for?High quality products. Get better performance for your Conveyor.Material: Metal Gear Lock A #43496A= 5 mmB = 24 mmC = 5 mm Gear Lock B #43502A= 4 mmB = 25 mmC = 4 mm Gear Lock C #43526A = 10mmB = 3 mmGear LockGear Lock Model:*Elegir