Replacement Bulb for Vintage Sewing Machines
BA15D LIGHT BULB

Push In, Double Contact, Bayonet Push Cap Bulb
Incandescent Filament Bulb

SBC = Small Bayonet Cap (b15d) base
PYGMY / SES

Dimensions:
Total Length:  58mm
Cap Length:  20mm
Cap Diameter: 15mm
Glass Diameter: 21mm

Will fit following Sewing Machines:

SINGER Featherweight 221k, 222k, 15, 15k, 15-91, 27, 28, 66, 66k, 99, 99k, 185, 127, 128, 185k, 192, 201, 201k, 201-2, 206, 237, 306, 319, 319k, 320, 328

and many others.