Diameter of Vixen LV 2.5 mm/1 1/4" eyepiece?

I'm thinking about buying this eyepiece as I've heard only good things
about it. Only problem is I want to use it with my digital camera for
eyepiece projection photography. My camera adapter is sized for a
standard eyepiece diameter of 33.7mm and I can't find any specs on the
Vixen as to diameter. Can someone who has one measure it with and
without the rubber eyeguard and post the measurements here?

Tia,
Ken Long
Albuquerque