17" Apple iMac. Reasonably confident it's the model at https://everymac.com/systems/apple/imac/specs/imac-core-2-duo-2.0-17-inch-s... but with the disk drive upgraded from 160GB to 500GB.
Untested, and the disk drive has been wiped, so you'll at least need to install an operating system. There are instructions for reinstalling macOS at https://www.ifixit.com/Guide/How+to+Install+macOS+High+Sierra/751.
Apple iMac 17" "Late 2006" Intel all-in-one computer (Enfield EN2)
This offer has been gifted to someone and is no longer available.