FMHXG Safe Box Emergency Battery Box External Battery Double Connector Universal Safe Backup Suitable for Various DC Devices Toys LED Lighting Power Low Voltage Electrical Equipment Maintenance 2.5

["Material: made of ABS plastic for durability and long life.","External battery packs with 2.5 mm jacks are only available for some safes, gun safes, and key safes with external battery power.","It holds four AA-sized standard alkaline or rechargeable batteries.","If the battery fails, the safe can be opened by inserting an external battery pack into the module on the safe.","The external battery pack is a regular AA battery pack, in series, with cover and switch for easy battery installation, perfect for your DIY projects."]