Nobody likes putting power down to their pedals, only to be surprised by a snapped chain. Help protect your chain with a guard sprocket like the Sunday Knox! The Knox is machined out of 7075 aluminum which is much harder and more durable than common 6061 alloy. The sprocket has been designed to work with beefy BMX chains, including halflinks, and is available in 25T or 28T. This simple design is an instant classic.