Compatible with the following Models / Part Numbers: Active Stylus Pen Battery Surface Pen Battery Surface Pro 3/4 Pen Digital Pen MS Surface Pen Digital Stylus Bamboo Ink Pen Stylus Pens Tooth Scaler Video Game Controllers Bluetooth Headsets A wide variety of household uses. Versatile Power For Your Household Electronics. Use them for everyday electronics such as alarm clocks, digital cameras, and universal remotes. Emergency supplies such as flashlights and portable radios Wireless video game controllers, remote controlled cars, and other electronic toys. Note: In order to extend battery life, please charge the battery first before using it for the first time and before long-term storage. The batteries can only be used with device and charger with protective plates installed. The capacity of the battery is 400mAh, please charge it in low output current mode to prevent over-charge and over-heat. Battery comes with low power due to transport security, it may reach top performance after 3 cycles of full charge and discharge. We recommend using the battery at least once a month, long term idle may shorten battery's life. Store it in a clean, dry, cool place away from heat and metal objects.