Empire Quality Replacement Battery For Streamlight SL20X, 600mAh, 6v 5 1/2 D stick. FLB-NMH-4 (6V 5 1/2 D Stick, Ni-MH 3500 mAh) Battery Replacement For Streamlight Flashlight Battery Made with high quality Japanese cells. 100% compatible with your OEM battery. 1 year warranty