There are lots of types of lasers out there ranging in colour and power. The highest handheld laser known for sale is 420mw.
If you are looking to purchase a laser you might what to check the spec's. Many laser from china come without IR these filters block Infrared light which is harmful to the eye. So always avoid theses ones, for example a laser may say 200mw but it doesnt have an IR filter this is the same as a laser with 20 - 30 mw.
If you are wanting to buy a laser it is worth knowing that green lasers are 50x more luminous in the dark then red lasers so you will be able to see it more clearly.
I hope this helps