Pros:
*Extremely cheap
*Melts plastic with ease
*178.7 mw average (I tested at my school) Don't let this turn you away because its still really powerful. Manufacturers rate the peak point, about the first 3 seconds when you turn it on and its a burst of light
Cons:
*NO IR FILTER!!! If you are going to get this USE WITH IR BLOCKING GOGGLES! They are cheap buy some. Your eyes can and WILL be damaged from just looking at the dot from 2 meters away. I have seen first hand someones eye vision go from 20/20 to 16/18 after a few months of exposure to IR light. This is NOT A TOY DO NOT TREAT IT LIKE ONE! Other than that, these are really really cool.
Other Thoughts:
Don't even think about shining it at someone. You can buy some IR filters that easy to install google them. A suggestion to DX, sell some IR blocking goggles/glasses atleast 5.0's or not at all :P or you could buy some IR filters and attatch them for like 50 extra (I think sufficient ones are like 40 bucks). Anyways keep the great deals going :P
Bottomline:
When using caution these can be pretty fun. This is an amazing deal though, and I would get another.