SL-B26 button top lithium ion battery with on-board safety control circuit - Micro-USB input; charges in 5 hours - Integrated safety circuit protects battery from overcharge/overdischarge - 2.75 in (7.0 cm); 1.7 oz (48 grams) - Use the SL-B26 USB battery to power the PolyTac X ProTac 2L-X ProTac HL-X and ProTac HL5-X and transform these multi-fuel lighting tools into rechargeable systems - Battery Type: SL-B26 Lithium Ion Battery - Battery Quantity: 1 - Length: 2.75 inches (6.98 centimeters) - Weight: 1.70 ounces (48.19 grams)