The Dead Level levels your reticle in relation to the Earth taking out any margin of error of the reticle not being perfectly level with the scope body. Simply attach your mounted scope to the Dead Level, level the device with the precision thumbscrews to center up the bulls-eye level, then just level the reticle with a predetermined level line or plumb bob. Aluminum Mil. Spec. Now features an Anodized Hard Coat Type III in a crimson and black finish. Instructions included. FOR USE WITH MIL STD 1913 PICATINNY COMPLIANT RINGS AND MOUNTS