These inserts are an awesome fix for stripped out threads anywhere we use 3mm screws. They’re machined out of brass and expand when the screw is installed. The knurls grab tight onto plastic and increases strength 2-3x over plain screw threaded directly into the plastic. A dab of CA upon installation secures them even further.
Drill stripped hole with a 5/32 bit, being very careful not to remove too much material. Keep drill bit inline with existing hole, use slow speed. Press repair insert into plastic with knurls inserted first until flush with surface. You can use a drop of CA glue on outside of knurls to create an even stronger repair. Be careful to not spread glue to internal threads. Walla! Repair completed!