The LiionWholesale Cold Weather Protected 3500mAh is a PCB protected button top battery. This is a 3500 mAh 10A battery that can be discharged all the way down to -40°C and is one of the best batteries we offer for high discharge flashlights or other devices that need a high capacity but medium discharge protected battery. It operates just as well as other high end 10A 3500mAh batteries at normal temperatures as well. Compatible with 3.7V Some companies market batteries like this as 3.7V 3500mAh, this will replace any 3.7V lithium ion with no issue. 3.7V vs 3.6V is just a labeling difference and is not an actual voltage difference inside the battery. All protected batteries are not the same - the Liion Wholesale version is the best protected 18650 on the market These are manufactured with a very high quality PCB including a Japanese Ricoh protection IC with three high end MOSFETs for 20A high current cutoff (most PCBs will not be able to handle this much current). This protection circuit protects the battery from mishandling, overcharge, or overdischarge while allowing the battery to do its job properly. The cell is made in Taiwan by a major cell manufacturer. Our company then adds the high quality PCB along with the button top in an ISO certified factory to all safety standards. A black wrap is put over the top to hold it together. Please note that these batteries have a UN38.3 test report available and are legal for shipping. Many protected batteries on the market actually do not have any test data and are likely illegal for shipping due to lack of UN38.3 test report. Many competitors don't realize that a separate test needs to be done on the battery assembly and that the cell test is not enough. All of our batteries include a UN38.3 report available upon request. If you need further certifications beyond UN38.3, I would recommend using our IEC62133, CB Scheme, and UL2054 certified Protected MJ1 Battery instead although its below freezing performance will not be as good. Cold Weather Protected 3500mAh 10A 18650 Button Top Specifications: Style: BUTTON top Approximate Dimensions (including button): 69.1mm length x 18.6mm diameter Brand: Liion Wholesale Manufacturer Rated Nominal Capacity: 3500mAh Manufacturer Rated Minimum Capacity: 3350mAh Manufacturer Rated Max Discharge Current: 10A Nominal Voltage: 3.6V Peak Voltage: 4.2V Minimum discharging temperature: -40 C Minimum charging temperature: 0 C PCB Protection: YES MOSFETS: Quantity 3 Origin: China Cell Certifications: UN38.3 test report, IEC62133, CB Scheme, UL1642 Battery Assembly Certifications: UN38.3 test report Priced per battery, not per pair. Receive free battery cases with your purchase! (up to 24 batteries, click to read our updated case policy.) We don't sell bogus batteries. When buying from LiionWholesale, you can rest assured that we only work with top tier manufacturers to bring you the best, most reliable, trustworthy batteries that will perform above and beyond your expectations. And we test every shipment to ensure consistent quality.