ENHANCED SECURITY FUNCTION: Quick release locking system with an adjustable 4digit code provides keyless access and straightforward operation, eliminating the need for keys while increasing protection for your bike and cycling gear. UNBREAKABLE SAFETY: Reinforced lock core and drillresistant alloy deliver strong, tamperproof protection with an anticut mechanism to resist forced entry effectively. SCRATCH SAFETY LOCK: Nonfading surface and scratchresistant coating plus a paint protection layer and wearresistant material keep the lock looking and performing well under daily use and environmental exposure. MULTIPLE OCCASIONS: Adjustable chain length and broad compatibility support various locking scenarios, with a builtin storage lock design to securely store helmets when not in use. Use scenario 1: Lock your bike outside a cafe or by attaching the chain to a sturdy rack and setting your 4digit code for quick, keyless access during a short stop. Use scenario 2: At a trailhead or apartment complex, adjust the chain length to secure two bikes or multiple frames, keeping them protected while you ride or work. Use scenario 3: During daily commuting, use the builtin helmet storage lock to secure your helmet along with the bike, simplifying your setup and reducing clutter.