This adaptation has proven itself in many areas of astronomy. The extension tube is simply screwed into the M48 filter thread from 2″ eyepieces or 2″ adapters and therefore will extend the barrel. Thus the fitting accuracy of an adapter can be improved.

These tube is also important for astrophotography when the correct distance between corrector and camera sensor is concerned. Here, often just a few millimetres are critical.

• barrel made of metal
• black anodized
• double sided 2″ filter thread (M48x0.75) – male/female
• optical path is 20 mm
• the outer diameter of the adapter is exactly 2″ – fits into the 2″ receptacle of focusers or adapters