Optimizer Ultra sight, the new Infinite Adjust Slotted Slide Bracket brings an extra level of adjustment that enables the shooter to make 2nd axis and vertical adjustments with ease. Simplify your sight in process and skip the frustration of jumping hole to hole; this new technology will allow you to fine tune at 20 yards and maximize your sight tape range.Compatible with HHA lens kits and HHA Blue Burst 2500 light;Scope Housing: 1-3/4";Mico windage adjustments left to right;Elevation adjustments can be made and locked down on the sight tape from 20 to 80 yards in single yard increments;Pin size: .029