Malcolm's question above is a valid one, as green lasers above 1mw are prohibited weapons, but those below are not! I use 1mw riffle green laser sights. Designed for fixed mounting. They are truly brilliant with vertical and horizontal adjustments, and with this power level, I can see the beam clearly enough off axis.
These cost between $35 to $45 delivered from China. Here is the one:
http://www.ebay.com.au/itm/UK-Tactic...ht_3589wt_1192
Now these pass customs, well I've had three ordered, and all units have been delivered.
Now I attach them to my mount hub pro for remote control on/off. That's so nice an option for initial alignments.
Steve