Male thread: M42x0.75; Female thread: M42x0.75; Eliminates a range of focusing problems
Use this extension tube for getting the correct image scale or the exact spacing required for reducers or field flatteners
The extension tube has a T2 interior thread and a T2 exterior thread for elegantly solving spacing problems in astrophotography
Compatible Cameras: Fits a wide range of Canon EOS SLR/DSLR cameras; including 5D; 5D Mark II; 50D; 60D; 20D; 30D; 40D; 350D; 400D; 450D; 500D; 550D; 600D; 1100D; 1D; 1D Mark III; Digital Rebel T4i; T3i; T2i; T1i; Xt; Xti; Xsi and Xs models
Telescope Adapter: One end of the T2 T Ring is M42 female threaded and the other is Canon EF-Mount; you can attach your camera freely to a 1.25 inch or 2 inch focuser of telescope by using a appropriate T-Adapter which is not include