Package for this heated warm knee support only includes 1 pcs, so we suggest you buy 2pcs at a time to use on both knees. Perfectly suitable for Christmas Gifts Father`s Day Gifts. [5V Powerful Rechargeable Lipo Battery Offers Unmatched Power ]- Almost all heating knee wraps in the market are powered by 5V batteries,which offers unmatched power to the heating knee pad. [3-Level Microprocessor Controller]- Red-White-Blue (40- 45 - 50) to adjust the desired heat level. A heating pad around 16 x 20cm with natural heat system. Adjustable wraparound knee brace. Perfect gifts for Mom Dad Men Women. [Where to Use]- Used to relieve muscular aches and joint pains associated with overexertion, strains and sprains as well as pains associated with arthritis, meniscus, osteoarthritis, bursitis, ACL PCL MCL tear etc. Also perfect for outdoor campaign, such as motor cycle, etc. [Safety]- Built-in thermal protection module. Once it is overheat, it would stop until the heat return to the standard temperature, so it is 100% safe to use. We know you will be impressed with our product and quality service, but if you have any questions or concerns, please contact us immediately.