Extended-length replacement black "acorn head" (rounded top) leg bolts for Williams, Bally, Data East, Sega, and Stern pinball machines.
These bolts are 1/4" (3 threads) longer than the standard leg bolt to accommodate the extra length needed for leg protectors, drink caddies, and leg plates with pim nuts.
Williams/Bally reference #4322-01125-40B.
Data East/Sega/Stern reference #231-5001-01B.
Jersey Jack Pinball reference #90-008038-40-0.