Used on a Harley. Used infrequently. Used about 2-3 times on touring trips. After that, it was stored in the garage. I checked with a motorcycle用品 shop, but the manufacturer is unknown. It appears to be a steel link lock. Diameter: 25mm Length: 134cm → (black part only) Key: Light battery replaced (with 2 spares) The photos are all that is included. Thank you.