The Thermic S-Pack 1400 Bluetooth battery for heated socks is the most powerful battery in the series. Thanks to Bluetooth technology, you can remotely control the heating intensity with your smartphone. Treat yourself to a complete solution and conveniently manage your Therm-ic products through your mobile phone. With the S-Pack batteries, Thermic PowerSocks heated socks can be heated for up to 16 hours. Thanks to the new Bluetooth feature of these batteries and the Therm-ic Mobile App, you can adjust the heating intensity of your socks, insoles, and gloves in real-time. This way, the performance of your product is perfectly tailored to your specific activities: skiing, hiking, trail running, mountaineering, trekking, etc. For you and your loved ones: your app can manage up to 4 user profiles and up to 4 Thermic heating products. The Bluetooth function makes handling your batteries easier and ensures optimal user comfort. Your feet will stay pleasantly warm for up to 16 hours. Battery pack with USB charger, wall charger not included.