b'Description: Features: It offers 1.25 inch mounting sizes on telescope side. The .M42x0.75mm has an external thread on one end and a standard 1.25 (31.7mm) accessory on the other end. The inside of the adapter is fully threaded to minimize reflections. The thread accepts a standard 1.25 eyepiece filter. Main for focus photography - use the camera directly. Simple Barlow Projection - Use your Barlow and camera above. Eyepiece projection - Use the eyepiece in the extension tube. Extended Barlow Projection - Use the extension tube with Barlow (expanding the Barlow projection to make 2 times the Baal to 3 times or more Barlow). compatible: for Sony/Minolta -mount camera A99 A77 II A330 A380 A500 A550 A450 A290 A390 A560 A900 A850 A100 A700 A200 A300 A350 A230 A33 A55 A35 A65 A77 A57 A37 A99 A58 etc........ A telescope with a standard 1.25-inch eyepiece port. Specifications Product name: Telescope Extension Tube Color: black Material: aluminum Size: as the picture shows Sleeve interface: 1.25 inches (about 31.7mm) Thread Size: M42*0.75mm Note: Transition: 1cm=10mm=0.39inch Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Include:(other accessories demo in the picture is not included.) 1 x Telescope Mount Adapter 1 x T-Ring for sony 1 x Extension Tube'