The device comes as it comes. It was on the boat when I bought it. Two failures in 18 years; none once I discovered and applied the solution about 16 years ago! Of course, we've never been all that far offshore where "loss" of the AP could really "hurt" if not repairable at sea.A couple of things. First, I don't think you should connect the drive to the quadrant; Edson is quite adamant about this. I used, as recommended, a separate bronze tiller arm. Second, mine was set up with a spring-loaded clevis pin with a hitch pin over a washer holding it in, so one can pull the pin in case of a jammed drive unit to free it up.
I can slap-in that spare drive underway, as long as I'm not single-handing, or even then, if I can balance the boat with the sails, or heave-to.