This is a great MaxView 40. This piece is optically perfect; The only 'flaw" on this unit is that there are cracks in the rubber grip-ring. This is purely aesthetic, nothing whatever to do with function or optics!
This eyepiece is especially designed for "Digiscoping", allowing the user to attach their digital camera to a telescope or spotting scope and turn their scope into a super telephoto lens! Great for birding and astrophotograpphy! The ep has a "T-mount" thread built in to it and the thread is hidden under the removable eyecup section. The MaxView is also designed with an adjustable eye relief.
The ep is the standard 1.25 size. To attach your camera, you will need one additional piece, a 'T-ring' of the proper size for your camera. Scopetronix is a good source for these.
I am selling one (in a seperate listing) in the 49mm size.
You can also use this eyepiece as a standard eyepiece for optical viewing and it provides an astounding FOV! Lots of info on the Scopetronix website, of course.
$100 shipped CONUS from 92106