You can see the image upside down but left-right correct with 90 degree while upright with 45 degree lens. Just simply insert the erecting lens into 1.25'' focuser and enjoy the nature far away: see the birds, deer at the edge of the forest, the summit cross on a mountain or a cruise ship far away on the sea…… Feature: Fit for 1.25'' focuser stand and eyepiece. 90 degree erecting images upside down but left-right corrected, and 45-degree images uprightly. Work well with refractor, Cassegrain and catadioptric telescope but not recommended for reflector telescope. With dust cover to keep the lens clean for crisp viewing and long time service. Specification: Angle: 45°  / 90° (optional)    Material: Plastic ' Metal  Size: 1.25inch Weight: 74-88g / 2.6-3.1oz  Package weight: 92-106g / 3.2-3.7oz Package size: 10.5 * 7 * 5cm / 4.1 *2.7 *1.9in Package list: 1 * Erecting Lens