Spring used on the shooter rod outside of the pinball cabinet. At 0.75" long, this barrel spring is a little shorter than the longer 0.875" barrel spring. This spring is used on all Data East, Sega, and Stern games as well as many Gottlieb, Williams, and Bally games.
Williams/Bally reference #10-149.
Data East/Sega/Stern reference #266-5010-00.