Its great mainly for the Moon when using an SLR. Don't know how it will go with a ToUcam. You might find you get too much magnification for your aperture.
I've got a calculation chart around here somewhere, if I can find it I'll let you know. It give the extended FL and magnification usinging different eyepieces etc.
The one I use is the Tele-extender similar to the meade one in the photo (but cheaper
). Does the same as yours but allows me to extend the tube to increase the focal length