CONSISTENT LEVELING FOR LONG RANGE ACCURACY The InSight Scope level quickly attaches to nearly any scope and helps keep the crossbow level for consistent shot to shot accuracy. It's lightweight, unique design can quickly and easily be installed on the scope making the level visible through the scope using peripheral vision.Fits all scopes with diameters from 1.495” -1.635” (38mm-41.5mm). Including Excalibur’s Overwatch, TACT-100, TACT-ZONE, DEAD-ZONE, GRZ2, SMF, SHADOW-ZONE, VARI-ZONE, DROP-ZONE.