M48/T2 extension tube 16.5 mm (M48 inside, T2 outside)

Various image plane and coma correctors often provide optimal correction at a sensor distance of 55 mm, meaning that the popular 17.5 mm backfocus ZWO and ToupTek astro cameras require a 37.5 mm extension arm to set the ideal distance. This distance can be achieved by using this 16.5mm long extension and the 21.5mm long T2/T2 extension. The adapter fits the corrector with an M48 thread, with a T2 thread on the camera side.