If you use with incandescent surefire ONLY the old school 80 lumen not the 60 lumen. If you use the newer 60 lumen one it will blow as soon as you turn it on after a full recharge on battery. 80 lumen bulb just fine. 120 Lumen incandescent doesn't even turn on due to lack of amperage out put from these batteries. Results of x2 Blue Tenergy RCR123A 900mah batteries.