Range Question

Hey all, I'm looking for a 5mw green laser just for fun, and possibly for a gun sight later

I'd like one with the most range, and was wondering why Z-Bolt is the only 5mw pointer to claim 5 miles, while the rest claim 2
I'm looking at these two models,
doing my best to post these links (first time post)

Z-Bolt BTG-10 Plus
z-bolt.com/BTG10plus-green-laser-pointer.html

Laserglow Galileo
laserglow.com/index.php?galileo

any help would be great!
Thanks a lot

novalasers has a good information about the range of laser pointers. novalasers.com/articlesrange.html

ive also heard good things about Laserglows galileo, but have no idea about the other.

Thanks for the reply,
as i thought, range is affected by the lasers divergence, power, and diameter of beam at source
the power for the two would be very similar 4.5-5mW

Diameter - Galileo : <1.5mm     -     Z-Bolt BTG-10: 1.1mm

Divergence - Galileo: <1.2mRad    - Z-Bolt BTG-10: does not say

Range: Galileo: most likely 10,000ft / 2 miles       -  Z-Bolt BTG-10: claims 5 Miles

I found a good explanation on wicked lasers website
wickedlasers.com/laser-tech/laser_beam_comparison.html

basically, beam diameter and divergence are inversely proportional, so we can't have small beam diameter and small divergence which would give the most range

it looks like the best balance between diameter and range is 1.1mm diameter and 1mRad divergence

from this, i guess Z-bolt's laser has a divergence of 1mRad ? why not advertise that

thanks for the help, Galileo looks like better quality of the 2