In order to get the best performance out of your bow, it must be fine tuned. The BowPlane 360 Degree Laser produces the most advanced bow and accessory alignment system ever. The BowPlane conveniently nocks onto your bowstring and sits on your arrow rest just like a normal arrow. When activated, the BowPlane projects a visible reference plane or sheet of laser light, 360 around the inside perimeter of your bow, up and down the bowstring, along the cams and/or idler wheels, upper and lower limbs, rest and sight pins too. This will let you know instantly if something is out of line.