Product Description: This handy adapter enables you to fit threaded accessories, adapters and focusers to a Maksutov- telescope with a rear thread. Allows you to use threaded diagonals, visual backs, reducers and other accessories on your - telescope. Has female Maksutov- threads on the inside all the way through and male threads on the outside at one end. Precision machined from aluminum and black anodized. External thread specification: external thread (2 inch-24 tooth British thread) External thread depth: 10mm (including about 1mm undercut groove at the bottom of the thread) Internal thread specification: Maksutov internal thread Internal thread depth: 12mm (internal hole all unified internal wall thread) Flange distance: 2mm Material: Metal colour: black Package Contents: 1 x Conversion Ring Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.