E means its a screw in bulb (Edison knuckle thread).I read online it can be an e5 or e14.
Some have the means to measure the mm's, so can we assume the measurement is the major diameter of the male thread? thanksE means its a screw in bulb (Edison knuckle thread).
The number is the nominal diameter in millimeters. E5 would be about 3/16" diameter, which is tiny. E14 would be 14mm diameter, about 9/16" diameter -- so if your E12 bulbs kinda screw in but are extremely loose -- then its an E14.