This is an accessory cable, which when used with a HelmetLok (sold seperately) will secure one or two helmets together OR your jacket and helmet. Pass one end of the cable through a convenient part of your bike, thread the other end through the loop then through the kit you want to secure. Use a HelmetLok or other lock to secure the end of the cable to your bike (see below)...done! When you’re done roll up the cable, slip it and you HelmetLok into the included neoprene storage bag and pop it your jacket pocket, top box or pannier. The cable is vinyl coated, 5mm in diameter and 1.5 metres long with a loop at each end.