I am not aware of any that are only 5 mW other than the new low-priced USB-powered ones.I am worried those are not safe, but maybe they are; I don't know.
Are there any other reputable lasers, preferably models that have been used in clinical trials?
Tinnitool isn't selling the 5 mW version anymore.
To verify the specifications, you can buy equipment that tests the output of the low-priced USB laser devices (and any other laser devices). This is one place that sells laser power meters:
https://www.laserbeelpm.com/products-1.html