Diaphragm, Control Block, to fit A-dec 500®; Pkg of 5 Replacement Diaphragm for A-dec® 4 handpiece block Package of 5 (A-dec® #38.1787.01) A-dec® and A-dec 500® are a registered trademark of A-dec, Inc. DCI has no affiliation with A-dec and A-dec has not authorized DCI replacement parts to be used on or in connection with A-dec® products.