Don't know what its called

Hello there. Could you send photos of the item in question? We'll do our best to help from there.

Thanks. This looks like a coil balance system--specifically, you have the 15-180 Pivot Shoe, 15-181 Double Carrier and 15-181 Drums, all sold separately. These parts work with Series 190 Coil Balance springs. See the videos below that shows how to remove and replace a similar setup, and also how to choose the right spring weights for the new coil springs. Let me know if you have questions.