T 2 external thread on the accessory side; safety groove to stop lens falling out
The light path is extended by only 3 mm; which is good news for the focus position as it is hardly changed
2 inch diameter T 2 focal adapter; fits into all 2 inch focusers
Improve Focusing Problem: The extension tube has a M48x0.75 interior thread and a M48x0.75 exterior thread; elegantly solves the spacing problems in astrophotography and improve a series of focusing problems
Variable Combination: The required spacing can be achieved by combining several extenders of differing lengths; Use this extension tube for getting the correct image scale or the exact spacing required for reducers or field flatteners