The new Rheostat Light Kit has eight different distinct brightness levels. With the rotating adjustment knob, hunters will notice the positive resistance as the light changes brightness levels for better control in low light situations. This Rheostat Light KitÆs adjustments eliminate the blinding pin fibers during the last moments of hunting. Each LED Rheostat Light Kit has sealed electronics to help eliminate any potential damage from wet, damp or cold temperature hunting conditions. 8 distinct brightness levels. Positive audible and physical position adjustment. Sealed electronics. Uses 3 size 373 watch batteries. Blue LED.Machined aluminum housing. Includes 4 different threaded bases to fit Optix, Apex, Truglo, Trophy Ridge, Copper John, Extreme, PSE, Viper and Sword sights.