Using your Kryptonite Kryptolok Combo Standard U - lock is easy. First, set your desired 4 - digit combination on the lock. To lock your bike, place the U - shaped shackle around the bike frame and a fixed object like a bike rack. Then, close the lock and ensure it clicks securely into place. When unlocking, enter your combination and pull the shackle open. It's important to note that this lock is designed for low to moderate crime areas. Avoid leaving your bike in high - risk locations for long periods. For maintenance, keep the lock clean and dry. You can use a mild soap and water to clean it if it gets dirty. Periodically check the shackle for any signs of damage. If you notice any issues, don't use the lock and contact the manufacturer for a replacement.