Medium, 5/8" tall, tubular rubber feet for amps/cabs. Metal washer insert for strength and stability.
Don't let the price fool you! You can certainly spend up to 10X the price on "brand name" versions of this stuff if you're into that, but these are made by the same manufacturer to the same specs as the "brand name" versions. The only difference here is that you're not paying for a brand name to be attached.
Package of 4. Screws not included.
See alternate photo for dimensional drawing.