The battery pack that transforms our high-performance multi-fuel lighting tools into rechargeable systems. – Battery Pack Features: – SL-B26® protected Li-Ion rechargeable battery pack with built in micro-USB charge port – Charges in 5 hours – Integrated safety circuit protects battery pack from overcharge/overdischarge – 2.75 in (7.0 cm); 1.7 oz (48g) – Use the SL-B26 USB battery to power the PolyTac® X USB PolyTac 90® X USB ProTac® 90 X USB ProTac® 2L-X USB ProTac® HL-X USB ProTac HL® 5-X USB Siege® X USB Stinger® 2020 Survivor® X USB Vantage® 180 X USB and more to transform these multi-fuel lighting tools into rechargeable systems