Male thread: M42x0.75; Female thread: M42x0.75; Eliminates a range of focusing problems
All metal construction and anodizing aluminium process for long time use
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 Pentax SLR/DSLR cameras; including Camera K-x K-r K-01 K-30 K20D K200D K2000 K1000 K100D Super K110D and other Pentax SLRs
Telescope Adapter: One end of the T2 T Ring is M42 female threaded and the other is Pentax K-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