As far as I know they dont make a beam expander for a Survival Laser. Please correct me if I'm wrong. So if they dont make one, then I guess you'd have to use a generic beam expander. And I wouldnt call ThorLabs, or some of the other makers generic. So I guess you are the one failing here.
It would be for 445nm. And I'm guessing that some of the available "generic" beam expanders work better on some hosts than on others. Which is why I was asking for specific advice.
The lmgtfy URL is humorous (I use it a lot on people too) but........ what I'm looking for is people who may have tried a generic beam expander on a host from Survival Laser. If there isn't anyone, that's fine.
Measure the circumference of the head of your laser. Most "generic" beam expanders will have adjustment screws to tighten on the head of the laser. Find one that will fit your laser. Then look for the highest light transmission for a 445nm beam available. Or at least what is available for your wallet.
They are out there, you just have to do some digging.