By beam trail do you mean, seeing a beam at night? If so, yes it will. Even a 5mW will. The higher the power, the better the beam. However, most cheap chinese companies are notorious for making underspec/non-consistent lasers. Really, quality varies, so the best way to tell if it's good is to test it. I'll leave it to other members to recommend some.
But, if you want, I have a couple of "FREAK" "5mW" lasers that are actually 50mW measured on my LPM (I have other "5mW"s that are 15mW, some are 10mW, some are 5mW). I'd sell you the 50mW measured one (not 100% accurately measured, but shouldn't be off by more than 10% or so) for $25 shipped. (It's in one of these kind of hosts:
5mw 532nm Powerful Green Laser Pointer Pen $11.56 - Free Shipping). Also, I'm in the US, so you'd get it much faster than china.
