The 2.5x Tele Vue Powermate is parfocal in All 1 1/4" diagonals and prisms making it better than a standard Barlow. It stands less than 3" out of your focuser and with fully multi-coated lenses you get bright high contrast images.

The 2" 4x Tele Vue Powermate is a better choice than a standard barlow for 2" diagonals because it is nearly parfocal. It is excellent with all 1.25" and 2" telescope eyepieces, but especially good with long eye-relief 2" eyepieces.

The 5x Tele Vue Powermate is ideal for long focus CCD and film photography and is a high performance alternative to eyepiece projection. It is parfocal in all 1.25" diagonals and prisms making it better than a standard Barlow.