"Customer came in with this at work. Seems to be 2 or 3 different compounds all encased in unopenable glass."
A: "This is an epoxy capsule used to glue a threaded stud into concrete. A hole of appropriate size (25mm in your case) to a specified depth.. he capsule is put in the hole and the stud is used to break , mash and mix the two part epoxy adhesive in the hole .. the other granules are to roughen the hole and aid in the mixing."
For you younger guys. Dating was much more fun before pantyhose.
It is used to keep the pistons from the disk brake caliper separated when the wheel is removed in case the brake lever is pushed accidentally.
It's from Adafruit, the company famous for their DD8008S and attempted takeover of Apple... so everything else is obvious.