Features: It can be turned on 4000 times under normal conditions and 150 times after under-voltage alarm. If the door cannot be opened after under voltage, the door can be opened with an external battery box. Suitable for sauna center, leisure villa, entertainment center, school dormitory, laboratory, etc. Stable performance guarantees the safety of your property. It is easy to carry with small size and light weight. Specifications: Condition: Brand New Optional Color: Silver, Golden Optional Type: W-shaped Bracelet Card, Silicone Wristband Card, Button Card Working Power: DC 6 V, 4 AA batteries. (Excluded) Quiescent Current: <10 microamps (μA) Dynamic Current: <150 mA (mA) Bolt Length: 15mm Diameter: Approx. 40 mm/1.6 in Height: Approx. 35 mm/1.4 in Applicable Door Thickness: 15~30 mm Working Temperature: -20 ° C - 55 ° C Material: Zinc Alloy Package List: 1 * Induction Head 1 * Lock Body 1 * Lock 1 * Screw Package 1 * W-shaped Bracelet Card 1 * Silicone Wristband Card 1 * Button Card 1 * Emergency USB 1、It can be turned on 4000 times under normal conditions and 150 times after under-voltage alarm. 2、If the door cannot be opened after under voltage, the door can be opened with an external battery box. 3、Suitable for sauna center, leisure villa, entertainment center, school dormitory, laboratory, etc. 4、Stable performance guarantees the safety of your property. 5、It is easy to carry with small size and light weight.