An optional part of the modular Astro T-2 system, the Alpine Astronomical Baader 2" SCT Male to T-2 Male Reducing Adapter is a solid and secure way to convert your standard male 2" Schmidt-Cassegrain Telescope (SCT) visual back threads to smaller T-2 male threads while adding just 1.5mm of optical length to your system. With the threads converted, you can unlock all the potential of the entire Astro T-2 family of adapters and gear to take your astrophotography and imaging to another level. From simple T-mounts and rings to extension tubes to the Heavy-Duty Quick-Changer Filter system, this adapter makes customizing your optical tube easy.