Signedplate on side of base: Western Electric / 10-D / LOUDSPEAKING / TELEPHONE OUTFIT / MADE IN U.S.A. PAT. IN U.S.A. / JAN. 18, 1921 OCT. 11, 1921 DEC. 13, 1921
Inscribedin red crayon on top of base: Z=26,500 ohms
in red on side of base: 1921
FunctionTransducing electrical signals into sound waves
Related Workshttps://www.radiomuseum.org/r/western_el_loudspeaker_10_d10.html