TS Focal Adapter TSFA240 from 2pol to T2, with 40 mm optical length The adapter fits into any 2pol receptacle and allows for connecting T2 accessories, like T2-rings for DSLR cameras or T2 adaptions (see recommended accessories. Additionally, the adapter adds 40 mm optical path. What sense make 40 mm optical path: Many telescopes with 2pol focusers have a focal plane far behind the focuser. First and foremost refractor telescopes, as they are designed for 2pol star diagonals. If you want to take photographs with them using a standard focal adapter, you have to extend the focuser far and possibly even have to use a 2pol extension tube. That reduces stability and causes tipping. The TSFA240 provides both functions in one adapter. It adapts from 2pol to T2 and is a 40 mm extension at the same time. That is perfect for photography. Further use as long adaptor from M48 to T2 for astrophotography Many correctors have a very long working distance from the M48x0.75 thread to the position of the camera sensor. The TSFA240 has an optical path of 75.2 mm from the female M48 thread to the T2-thread. The T2-thread is not taken into account, as it disappears in the connection adapter. Hence you can use the adapter for attaching your camera to corrector systems if the have a long working distance.