Feature: 1. Battery Reminder: When the battery quantity drops below 20%, the red light of the lock will flash and the mobile APP will also display a low battery prompt; When the battery quantity is below 10%, it will not be able to lock (normal use for about 8 months) 2. APP Control: Select automatic unlocking, no need to operate the phone. When the phone approaches, the blue light on the lock flashes to indicate unlocking status; When the phone leaves, it is in a locked state; Locking and unlocking by turning on and off BT 3. Alarm Release and Password Change: When the alarm is triggered, if the phone is close to the lock and connected, the alarm can be released (the phone BT and APP must be open); Six digit password setting, supports password modification 4. Multiple Functions: Can pair multiple mobile applications, easy to operate, as long as your phone is close to the BT chain lock to unlock; Equipped with vibration alarm function; Low power consumption, with low battery warning function 5. Water Proof and Practical: This chain lock has an IP44 water proof rating, making it suitable for any occasion; The alert sound is above 110 decibels, suitable for bikes, electric vehicles, motorcycles, and more Specification: Item Type: BT Chain Lock Material: Manganese Steel Chain, ABS Battery Type: 3 x AAA Battery (not included) Chain Diameter: Approx. 6mm / 0.24in Chain Length: Approx. 80cm / 31.5in Function: Anti Cutting Function: Alert when the steel rope is cut Anti Dismantling Function: Alert when the screw is dismantled Vibration Function: Alert for 30 seconds when the lock body vibrates or moves Water Proof Function: IP44 Water Proof Alert Sound: 110dB and above. Package List: 1 x Chain Lock 1 x Screwdriver 1 x User Manual