Brass compression ring; Built in brass ring and thumbscrew accessories avoid eyepiece to rotate during adjustments; effortless fixes more firmly and will not scratch your eyepieces barrels. Correct upside down and left right reversed image; the view image is upright; but left and right reversed if use the 90 degrees to your telescope. 90 degree viewing angle; diagonal reflects the telescope’s light path 90 degree to provide a more comfortable viewing angle; best for observing objects overhead. 1.25 inches nosepiece fits 1.25 inches telescopes; accepts standard 1.25in filters; eyepieces; Barlow lenses and other accessories with a 1.25in insert barrel. Dielectric coatings; super flat mirror with dielectric coatings to reduce reflected light loss; provide an over 99% reflective surface; good for astronomical viewing.

Country of Origin: China. Manufacturer: SVBONY. Date First Available: December 16, 2020. Best Sellers Rank: #3 in Telescope Diagonals. Customer Reviews: 4.6 out of 5 stars 93 ratings 4.6 out of 5 stars. Item model number: FF9171B. : B08QRY4V97. Item Weight: 7 ounces. Product Dimensions: 4.4 x 3.3 x 2.4 inches.