Labmax isn't a service you mail off a sample to. You purchase the testing kit and perform it yourself.
You put a couple drops of your Test in a vial with a reagent, wait 15 minutes, then hit it with a black light of a specific wavelength. If it tests positive, it will fluoresce brightly. if it's less pure, it won't be as bright. If it's not test, it won't glow at all.
You can also test tren, anavar, winnie, etc this way.
There's also a company associated with DanceSafe that used to only test ecstasy. For $100 they'll test whatever pill you send them, but they won't tell you the purity. This was done in agreement with the DEA so that dealers don't use the company as quality control.
At the source board I go to, the sources mass spec their raws and will also credit any customer who Labmax's their product or gets bloodwork done and posts the results.
Oh, and fuck PM, that site is the worst.