Enhanced security with a 4digit adjustable code access and a quickrelease lock system that eliminates the need for keys while improving protection. Sturdy locking system for dependable theft protection. Features a tamperproof lock with anticut mechanism, crafted from drillresistant alloy and a reinforced lock core. Allweather durability and longlasting appearance. The sturdy paint layer and wearproof construction resist scratches and fading, keeping a sleek, clean look during extended outdoor use. Flexible, versatile design for multiple bikes and accessories. A flexible and adjustable chain mechanism secures several bikes and supports multiple scenarios, with practical helmet storage and compatibility with common lock standards. Use scenario: urban commuting and rack locking. Lock your bike at stations or racks quickly and securely using the keyless code, avoiding key management. Use scenario: multibike households or bike fleets. Secure several bicycles with one adjustable chain, suitable for families, shared bikes, or small bike fleets. Use scenario: outdoor trips and helmet storage. While you ride or rest, the system provides a practical solution for storing helmets and securing gear, with broad compatibility for standard locks and racks. Function, compatibility, material, and performance at a glance. 4digit combination access, quickrelease locking, tamperproof and anticut features, drillresistant alloy core, adjustable chain mechanism, wearproof finish, scratches and fading resistance, compatible with standard lock setups and common racks.