Worth their weight in gold! Before you make a decision, check Ebay. The one we got for our HTT was, IIRC an Ultra 3500 refurb, and we paid right at $100 for it. Never had any issues. When we got the TT, went right back to Ebay and can't remember this brand, but one of the better ones and also a 3500. This one was brand new in original packaging and was around $125 or so. You can save yourself a bunch. I would not be concerned at all about a refurb. Many have bought them and no complaints...just happened the one we wanted this time was a new. Installation is maybe a 30 minute job and not difficult at all. One thing you want to do regardless of brand, is to have a supply of fuses for it. The electric jack was not part of DH job description and he either raised or lowered too far and the fuse popped. Thankful to have a great camping family next to us and the DH took him to Walmart for fuses. Lesson learned....we have multiple fuses for everything on the truck and TT.