Sylvania Press 40 replacement bulb
The Sylvania Press 40 was a smaller flashbulb than the Sylvania #2. GE had a similar version called the GE#11 flashbulb. Philips made a similar sized flashbulb called the Philips PF45 flashbulb and was classed as a focal plane flashbulb. All these flashbulbs had the ES medium screw base.