Don't forget the T-Ring adapters to get the design amplification factor.
See
http://www.televue.com/engine/TV3b_p...d=123&Tab=_con and
http://www.televue.com/engine/TV3b_p...d=123&Tab=_app and
http://www.televue.com/engine/TV3b_p...d=123&Tab=_acc
The top eyepiece housing unscrews and the T-Ring adaptor replaces it. One available for 2" 2x, one for 2" 4x and one that does both 1.25" 2.5x and 1.25" 5x.