The T-4 rechargeable light from Inova (Emissive Energy) is a 9-inch O-ring-sealed aluminum multi-function light. Its body is completely checkered, with the push button located near the light bezel. This allows you to operate the light with either your pinky finger or thumb with ease. The ease of operation means the T-4 is a good light for use with your weapon if you use the Harries method. The T-4's lithium-ion battery will run for up to two hours, and I have found the batteries to hold a charge for many weeks. Once the batteries are drained they will recharge in approximately a half-hour. At full power the T-4's light is visible for up to three-and-a-half miles with useful light out to 100-plus yards.