|Diameter of inner thread||3.17cm/1.25inch|
It offers 1.25 inch mounting sizes on telescope side.
Outer and inner thread, one side is to fit T-ring, the other side is 31.7mm(1.25''), which fits for telescope mount adapter.
It is compatible for Canon camera
1 x Telescope Mount Adapter
1 x T-Ring for Canon EOS
1 x Extension Tube