Harbor Freight sells cheap Chinese knock-offs of otherwise quality built tools. They are OK if you are buying them for just a few uses. I would not depend on them much after that. They do honor the warranty, but it doesn't do much good unless you are sort of 'around the corner' from a store.
I bought a hot air plastic welder from them for $29.95 that was an exact dupe of a $399 US unit. It basically works, but needed to have a part replaced on first use. Since they are a long distance from me, it was cheaper to replace the bad regulator with a US made one for $50. The welder now works great....just like the expensive one, just less expensive!!!
I would go for it if you will only use it once-in-a-while. You can't go wrong for $20!