Patented in 1994, the Predator IV is still the most advanced bowhunting sight ever!! No other system has five means of adjustment to calibrate the system exactly to the individual bow. The last three adjustments must be made at treestand level, (around 15ft.). Then, for ground shooting it will be accurate around the 30 yard point without any lock down. Predator IV sights are equipped with stainless steel ball bearing for smooth noise and trouble free performance. Includes the new Starlite Pin with 8 inches of .040 Truglo Fiber Optic.