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 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. Made from Aluminum with Mil. Spec. Anodized Hard Coat Type III, crimson and black. Instructions included.