Part of the Astro T-2 Modular System, 32mm Clear Mirror Aperture, T2 Male and T2 Female Threads, Highly Reflective Mirror Coatings A part of their modular Astro T-2 system the Alpine Astronomical Baader T-2 90 Prism Star Diagonal Housing is offered in this configuration to give you complete customization options for a range of applications. The 32mm clear aperture mirror diagonal housing has T2 male threads on one side and T2 female threads on the other. These are compatible with the Astro T-2 family of accessories from photo and imaging adapters to eyepiece holders ClickLock holders nose pieces and more. Highly reflective mirror coatings limit light loss to ensure images remain bright and clear while the simple mirror design corrects images horizontally but leaves them laterally inverted.