I had a need for some good collimators for my dual red project and picked up a set of these from DrLava...
WOW! They not only look good, but work good too! The body is made out of brass I suspect and plated to reduce reflection. This is also a multi lens collimator! (at least 2, maybe 3 lens!) The lenses are also AR coated all the way through.
As for results, I'm not an Aixiz module lens specialist but they most definitely out preform the stock plastic lens collimator. The beam is tighter with less anomalies and has less loss. I gained 10mW on a LOC 660nm diode outputting 140mW.
So what's the catch? Nothing! For $10 you get a truly awesome collimator!
Where can you order these fine collimators? Check the link...
http://hacylon.case.edu/ebay/laser_diode/Lens.php
Thanks!
Adam