It can also be used in other 3.7-5V electronic products with power less than 2.96Wh (800mAh).( Not applicable to high-power electric tools and model aircraft) Please carefully compare the polarity of the connector before use, the red wire is the positive "+" and the black wire is the negative "-"White wire is thermistor "NTC",Do not reverse-charge or reverse-connectreverse. The primary battery of some products has no plug or mismatched plug or mismatched polarity. It doesn't matter, you can cut and solder the plug directly or use our heat shrinkable insulating sleeve to connect the same color wire. 603040 rechargeable lithium ion polymer battery, nominal voltage 3.7V, full charge voltage 4.2V, capacity 800mAh, power 2.96Wh, size 40.5×30×6mm(1.594×1.181×0.236inch)(L*W*T), Weight:13.7g(0.487oz),Maximum current:0.8A。 It can prevent overcharge, overdischarge, overcurrent, and short circuit. It‘s consists of of large-capacity A+ lithium battery, Japanese Seiko IC overcharge and overcurrent short circuit protection board, 3 wire 3302-26 high temperature resistant silicone cable module. Package:603040 800mAh LiPo battery x 1,heat shrinkable insulating sleeve x 1 Compatible with Marshall MID Major II Major III Major IV Bluetooth Headphones Battery Replacement VDL603040 SR603040。 It can also be used in other 3.7-5V electronic products with power less than 2.96Wh (800mAh).( Not applicable to high-power electric tools and model aircraft) It can also be used for MP3, MP4, MP5, GPS, Watch, power packs, detectors, recorders, Bluetooth mice, Gaming Headset, speakers, e-books, LED lights, sensor lights, Parking Monitor,Car Driving Recorder, portable DVD, radios, toys,Network Box,USB Fan,Tester,air Purifier,controller,bluetooth speaker, dash cam, keyboard and mouse, Wi-Fi enabled smart home systems, PDA and digital cameras, monitoring units, notebook computers, e-books,telematics,tracking devices, sleep management equipment, blood oxygen More. Other 3.7~5V electronic products with power less than 2.96Wh (800mAh). Size:40.5×30×6mm(1.594×1.181×0.236inch)(L*W*T) Capacity:800mAh Weight:13.7g(0.487oz) Maximum current:0.8A