Sega/Stern Flipper Extension Spring
Ships from US and is sold by Pinball Life$0.75
Used in some Sega Batman Forever Games and all Sega games thereafter. Used on all Stern games 1999 to present.
This spring looks almost identical to a Williams/Bally flipper extension spring, but it is much stronger.
Sega/Stern #265-5035-00.
American Pinball reference #9654K106.