Steve,
There are different versions of it depending on whether it comes with a mount, but the OTA-only version is this:
http://www.celestron.com/astronomy/c...-xlt-cg-5.html
The "CG-5" designation means it has a Vixen-style dovetail (i.e. would fit the Portamount). Some Celestron tubes have the "CGE" dovetail which is wider and doesn't fit the Portamount, etc.
Note that the OTA in the picture appears to actually be the C8
