Digit combination lock. This bicycle lock does not require a key and is unlocked with a 4-digit password combination, which greatly improves the security factor compared to key locks. Convenient and safe. It adopts high-quality manganese steel chain, which is strong and firm, ensuring maximum safety. The inner lock core is made of alloy, which is fully anti-sawing, anti-drilling, corrosion-resistant and wear-resistant. High quality pull ring, universal diameter 6mm, wrapped in coarse cloth. High quality pull tab, effectively prevent your bicycle or other tools from being stolen. Easy to use. There is no need to carry the key with you to open the lock. You only need to set the password and you can use it, which is very convenient. Password can be reset. Applicable to a variety of areas, it can be used for motorcycles, electric vehicles, bicycles, iron sliding doors, and glass doors. This is a great tool for protecting your property.