Hi,
One of our members, Blakehoo, uses these. There really is no difference from the usual models, other than the extension tube for the scope. I had passed my E-series units on to him some time ago because he was still using the series in his biomedical research work.
This is a case of making a system out of the camera and scope, both of which existed as stand-alone products. At work, I use a similar setup with a Nikon trinocular scope and a Nikon video camera module hooked to a dedicated PC. At home, I have an older binocular scope with an adapter that replaces one eyepiece and hooks a Kodak DCS 560 up in place of my eye. So, that one works more like this setup than my more modern version at work. It's cheaper that way!

Stan