I just bought a Chineese green laser pointer, it cost about 8 bucks. It has 3 labels: one thet says >5000 mW (obviously fake), one that says <5mW, and one that says <1mW. It's clearly more than 1 mW and i think it's moe than 5 mW but then how powerful is it? How can I find out whitout buying specialised tools?