Cisa 28550-67 Lock

Using the series IV outdoors for 2 years now and there is no sign of corrosion what so ever! Needless to say my bike has never been stolen either. This chain is the business so don't waste you money on something else, there is just no point.

Very solid, Easy to use and cant see anything short of tactical nuclear weapons even marking this. The design means the chain protects the bolt. About the only way to improve this would be to have the bolt self lock when you push it in, as you have to actually lock it with the key

Very positive locking, easy key insertion