UTG Add-on Index Wheel for Side Wheel AO Scope, 80mm Features: - UTG 80mm Diameter Side Wheel Add-on for Making Finer Parallax Adjustments - Compatible with Side AO ACCUSHOT Optics and Not Compatible with Bubble Leveler Side AO ACCUSHOT or Side AO BUGBUSTER Optics - Aids in Finely Tuning Parallax Adjustments - Aircraft Aluminum Construction with a Matte Black Anodize - Laser Engraved Distance Markers in Yardage Increments Specifications: - Compatible with: Side AO ACCUSHOT Optics and Not Compatible with Bubble Leveler Side AO ACCUSHOT or Side AO BUGBUSTER Optics - Length: 80mm - Height: 80mm - Material: Aluminum - Weight: 1. 4