From the FAQ:
Is that FAQ entry correct? If so, then the OD 2.75 goggles will be nowhere near enough for a (say) 400mW laser... right?What does OD mean? OD means Optical Density. Basically, the higher the OD rating on the goggles, the less light will be allowed to pass through. OD3+ goggles are fine for lasers up to 125mWs. Further than that, you'll need goggles with progressively higher OD ratings.