I'm not sure where the line ends from engineer to manufacturer but for the most part, this design is decent. It does what it is designed for, but the manufacturing level seems as if it went to the lowest bidder. With a little manufacturing management, this would be an awesome device. It wouldn't take much to make it a quality item.It meets a need at a price point that has no equal, so there isn't much if anything to compare this to.My unit came and had a small problem that the seller took care of right away and with good attention after I contacted them. This is for the Happybuy Trailer Mover 350W. I suspect most people that own a trailer, have a bit of DYI or "make it work" attitude, and an owner of this item will benefit from that attitude while being able to move their trailer for much less cost than some of the other available options.