Best lens for a GWEIKE 100W laser?

[John Finnegan]

I'd like to get a couple replacement lenses (67mm) for my laser and was wondering if anyone had any suggestions.

Is it possible to 'upgrade' the lens from the Chinese version that shipped with the laser? Is there a better US equivalent lens that would provide a noticeable bump in performance?

Also, does anyone know offhand what size diameter lens I should be looking for?

Thanks,
John

[Dave Sheldrake]

20mm diameter

RMI and II-VI also make great lens's but they do cost a lot more (think $120 for II-VI and 200 to 300$ for RMI)

To be honest...unless you plan on doing some real precision stuff with a top flight tube there isn't much benefit.