When you search green laser gun sight, you can find many of them on Amazon , most of them are 5mW, because the laser with output power > 5mW is forbidden on Amazon or eBay.
The green laser beam is so powerful and bright that the 5mW output is enough for regular shooting use.
This 200mW green laser sight is the most powerful one, it produces highest output power laser beam .
most powerful green laser gun sight