This is an 8000 step encoder package from JMI. I sold the scope recently. I had it on a C8 basic but JMI says it fits the deluxe as well.
Check the picture for the RA axis encoder; the use of a belt allows the OTA to swing through the axis, allowing proper parking of the scope, even with the dust cover in place. Celestron's encoder kit does not allow this.
Kit includes a computer tray, though I never used it because it doesn't fit the wedgepod I had; it requires a separate wedge and tripod and fits between the two.
Includes the brackets, encoders, and a velcro'd on plastic cover for the dec encoder (see picture) and a couple of tools needed to mount the kit; also includes the encoder cable. You just install and add the computer of your choice.
New price from JMI is $275, I'll take $200 including shipping or make an offer.