APM 3 inch diagonalprism , 3" connection on both sides, incl. adapter 3"/2". A large 3" Zeiss prism with T coating was used. Free optical passage 69 mm, weight without adapter 3"/2" 1471 grams , with adapter 1782 grams, optical path length approx. 155 mm to 3" end and and 165 mm to end 2" adapter.
APM-Telescopes manufactured mechanics, made in Germany, paired with a 2" zenith mirror also of German manufacture with a quality of 1/20 P-V surface provided with the best and most expensive mirroring Germanya a Tafelmeier- 96 % reflection.
Altair Premium Positive-Lock Diagonal - Dielectric 2 inch Pushfit The Altair 2" premium diagonal with positive-lock system grips 2" accessories tightly with a small rotation of the top knurled ring, keeping them precisely centred. The CNC machined chassis will hold extra heavy accessories without flexing, and the mirror features a premium 99% reflective dielectric-coating. Ideal for refractors and large eyepieces or binoviewers, the positive-lock has a very light action and only needs a small 20 degree rotation, letting you quickly replace accessories. There's no need to apply excessive force on thumbscrews or normal twist-lock mechanisms to insert accessories. Once you've tried it, you won't want to use any other diagonal again, it's that easy. Other features: Includes a 2" to 1.25" adapter with compression ring for smaller eyepieces. The 2" Pushfit barrel is precision machined and is threaded for use with standard 2" astro filters (M48x0.75mm thread). Blackened interior for high contrast observation of bright objects. A scratch resistant chemically stable dielectric mirror coating enables more frequent cleaning than softer aluminium-coated mirrors. Super-hard black anodising for extra durability. Includes dust caps for both ends, and a foam filled box. Scope of Delivery: Altair Premium Positive-Lock Diagonal - Dielectric 2 inch Pushfit Specifications: Filter thread: 2" / M48 Connection to eyepiece: 2" and 1.25" compression ring Connection to telescope: 2" with integrated M48 Thread Weight: 500g