10 inner valve seats for the Beckwith brand player piano mechanism.  Originals were made from 1/8" fiber but for cost reasons we made these from 1/8" hardboard.  Dimensionally, these are the same as the originals.  

I'm Howard Gustafson and I've been a player piano technician since 1985.  I'm glad to answer questions about this item (or any other item we sell or you think we should sell) before or after your purchase.  My contact information is included with each shipment and you can also reach me through eBay.  Your success with my products is very important to me, please don't hesitate to contact me with questions or suggestions.