Do you mean like this one?
RM01 Trijicon RMR Tactical Red Dot Reflex Clone w Picatinny Rail Mount 719307605510 | eBay
I wouldn't chance it, mainly since they put "trijicon" on it, it's most likely meant for airsoft.
I think for that price I'd look at something else in the $100 range, go to ebay and do a search for " bushnell red dot " and you'll see what I mean, I'm sure there's other good red dots for that price range too.
If you not in a hurry also check out the venders that always have sales, sometimes you can get the last generation one for half the new price.