Explore Scientific 2in HR Coma Corrector. This Explore Scientific 2" HR Coma Corrector for Newtonian offers multi-coated lenses a black-anodized aluminum barrel with spacer markings and a textured rubber grip. The Explore Scientific 2in HR Coma Corrector comes with three thumbscrews two adapters (.75" and 1") to secure to your T adapter and a protective cap so you can finally get to view the fruits of your astrophotography labor. Specifications for Explore Scientific 2" HR Coma Corrector for Newtonian: Weight: 1.4lb; .64kg Diameter: 69.3mm Length: 147.2mm Package Contents: Explore Scientific 2in HR Coma Corrector HR Variable Coma Corrector; 2.0-inch O.D.