This is a high-performance replacement flashlight battery for the Streamlight SL20X, guaranteed to meet or exceed the OEM specifications of your original. The flashlight battery is 8.37 x 0.91 x 0.91 inches with an output of 6 volts. The chemistry is NIMH at 3500mAH capacity. Manufactured by Empire Scientific, model number FLB-NMH-4. We offer a 1 Year Warranty with purchase. See this product elsewhere at a lower price? Call or email us; we have a Price Match Guarantee.