Window Part Item?

Hi - I have several windows with this piece broken off and am looking to find the replacement part to fix the window if possible. The windows either don't open but a crack or open and fall. Windows are interior width of 34" and height of ~58". I believe this part may be some type of spring coil balance. Thanks!

I think I may have figured out what I need but want to confirm since there are no markings on my pivot shoe. There are three coils that have #4.0 35 listed so I think the top parts may be 15-205 3/8" Egress Coil Triple Support with 3 S165-4 4 lb Series 165 Egress Coil Balances. The pivot shoe has no markings other than a patent number but the closest thing to the attached picture looks to be a 15-199 Pivot Shoe, 17/32" Thick.