Celestron CG-5 Mount, with dual axis drives and 2160 step encoders installed. Works well with an NGC-Sky Vector or any of the others using the same control box. The objects come up in the eyepiece of my 4 inch refractor every time. The encoders with mountings are worth over $100 by themselves. $325 + shipping.
A 10# counterweight is also available for $30 plus shipping. You will need this to balance a 4 inch refractor!
A 6 volt rechargable battery pack is very handy to have and can save you a bunch on 1.5 volt D cells over a Summer's observing. You can have this one for $30 plus shipping