The additional components that come with both 140c and 140HD are pretty much the same. They include a Magnum gun, gasless and gas nozzles, a cable liner, a work-cable with a clamp, spindle adaptor, hose, and adjustable gas regulator, drive rolls, wire guides, and sample spools of mild steel MIG wire and flux-cored wire. You also get a DVD with instructions and the guidelines on using the machine.
The only difference is that Lincoln 140 HD includes a Magnum 100L, while 140C features Magnum Pro 100L. Also, the latter model features diamond core technology and industrial cast aluminum. In contrast, this tech feature is missing in 140HD, and it has a heavy-duty cast aluminum wire drive.