Shimano Shimano B01S Resin Disc Brake Pad and Spring, 4th version of B01S pad, fits many Deore, Alivio and Acera Calipers - Philbrick's Ski, Board, & Bike
Amazon.com : SHIMANO B01S Resin Pad & Spring : Bike Brake Pad Inserts : Sports & Outdoors
Shimano Deore B01S / MT400 Resin Pad & Spring - Urban Pedaler