Bitzenburger precision die cast clamps are available in three different models. Straight clamps for offset as well as straight fletching, right clamps for true right helical fletching and left clamps for true left helical fletching. ◾Each clamp is precision ground to assure identical blade matching. Right and Left helical clamps are ground with a radius to achieve a true helical fletch. ◾Hollow recess allows for thumb and fingertip control preventing slippage in the hand. ◾Graduated scale at the rear of the base of the clamp to allow for consistent spacing of feathers and vanes accurately from the nock. ◾Knife edge on base of clamps eliminates build up of surplus glue.