Helmet lock with T Bar combination lock - The Helmetlok can be used to lock your helmet to your bike. Use the T Bar Extension if you have a ratchet/quick release helmet. The extension slips into the "quick release" buckle and the Helmetlok fits through the hole and onto your bike! The ORIGINAL Helmetlok is a secure lock, once you put in your code, it cannot be changed unless you use your original code to change the numbers.