1 bass damper head felt for two string upright piano unison (two strings on the same key). Usually used on the higher notes of the bass section (wound strings) but some pianos also have them in the low tenor section wound and unwound.  1 3/8" long, 3/8" wide.

I've been a tech 30+ years and am glad to answer questions before and after the sale - my contact info is included with each shipment and you can also reach me through eBay.