"Huge old wooden hammer. Handle 30” long. Weighs 15lbs. What was this hammer used for?"
A: "It’s a wooden maul, 15# I’d think it was used for pounding large wooden stakes into the ground. Used one decades ago when me and some friends were helping a carnival setup."
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.