Just short of 3-1/2" long. 7/16" wide. Blued spring steel. Have a push button that falls through or isn't working or staying in place?. Check the spring, visible under the keybed.
1 Player Piano Phenolic Disc 1/64" under 1-1/4" OD, 1/32" Thick, Circle
1 Player Piano Phenolic Valve Disc 1-3/8" OD, 1/16” ID, 3/32" Thick, Tan, Circle
1 Player Piano Phenolic Valve Disc 13/16" OD, 11/64" ID, 1/32" Thick, Circle
1 Player Piano Phenolic Valve Disc 1/2" OD, 0.055” ID, Tan, Circle
1 Player Piano Valve Disc 11/16" OD, .050" Thick, Aluminum
1 Player Piano Phenolic Valve Disc 3/4" OD, 3/32" Thick, Tan, Circle