The Orion 1. 25 inch Twist-Tight Dielectric Mirror Star Diagonal gives the typical thumbscrew-equipped telescope diagonal a new twist - literally! This innovative diagonal features a twist-tight clamping mechanism that securely grasps inserted 1. 25 inch eyepieces and accessories with a simple clockwise twist of its red aluminum collar. Unlike thumbscrew-equipped diagonals, the Orion Twist-Tight diagonal delivers equal inward pressure to precisely center eyepieces, camera nosepieces, and other equipment along the light path of the telescope with a more robust grip. What's more, since this diagonal doesn't use a thumbscrew, you don't have to worry about annoying scratches or gouges appearing on your treasured eyepieces, and there's no thumbscrew to lose in the dark! The easy-grip, knurled aluminum twist-tight collar is delightfully easy to adjust, even while wearing gloves during cold nights. The Orion 1. 25 inch Dielectric Twist-Tight Mirror Star Diagonal is built around a highly reflective mirror with sophisticated, lab-tested dielectric coatings providing 99% reflectivity. With such high reflectivity, this diagonal will help you obtain the brightest views possible through a refractor or Cassegrain telescope. The 1. 25 inch Twist-Tight Diagonal's rugged anodized aluminum housing features machine-threaded internal baffles to ensure optimal contrast and also eliminate pesky internal reflections and glare. What's more, since dielectric coatings are more durable than enhanced aluminum coatings, you'll enjoy year after year of exceptional performance without degradation. The diagonal's 1. 25 inch nosepiece barrel is conveniently threaded to accept like-sized filters so you can easily swap between different telescope eyepieces and other accessories without the hassle of re-attaching the filter each time. Protective caps are included to keep the diagonal free of dust when not in use. Please note: diagonals are not recommended for use with Newtonian reflector telescopes.

Nosepiece barrel threaded to accept 1.25" Orion filters. Machined and anodized aluminum housing features machine-threaded glare baffles to eliminate glare for great performance. Durable dielectric mirror coatings provide higher reflectivity for maximum brightness and contrast. Twist-tight clamping mechanism grips inserted eyepieces more securely than typical thumbscrew-equipped diagonals - without scratching!. 1.25", 90-degree mirror diagonal features sophisticated dielectric coatings with highly efficient 99% reflectivity for peak performance.

Water Resistance Level: Not Water Resistant. Photo Filter Thread Size: 38 Millimeters. Material: Aluminum. Brand: Orion. Manufacturer: Orion. Date First Available: November 1, 2003. Is Discontinued By Manufacturer: No. Best Sellers Rank: #7 in Telescope Diagonals. Customer Reviews: 4.2 out of 5 stars 33 ratings 4.2 out of 5 stars. Item model number: 40901. : B01LWJM739. Item Weight: 8 ounces. Product Dimensions: 4.5 x 1.75 x 3 inches.