First Laser

Hi, I want buy my first laser(2000mw): Aliexpress.com : Buy oxlasers 100mw OX G101 star Green laser pointer PEN with visible beam +FREE SHIPPING from Reliable pen plastic suppliers on OXLasers's Online Official Flagship Store
I have a question: What is exactly 445nm/447nm/450nm?

It is the wavelength in nanometres, the colour.
445nm-450nm would be blue, as you can see from the picture down below.


And don't buy from them they are over priced and deceiving in there description they say by 2000mw they mean 1500mw. SFlasers is having a crazy sale so I would get a laser from there, they have 1W at $90, 1.3-1.8W at $110 and 2W-2.4W at $150.
http://www.sflasers.us/SF501B_445nm_Blue/p2035127_9480307.aspx

thanks what power you advise me to take?

I think this shipping is very safe for customs
Seperated Shipping - Send the laser disassembled in two packages

Just take what ever power you want, he even sells a 2.5W-3W or 3W+. One thing YOU NEED is saftey goggles Eagle Pair® 190-540nm Slip Over Laser Safety Goggles or Eagle Pair® 190-540nm Standard Laser Safety Goggles the only diff is one can fit over prescription glasses.