What is this?The miniature bulb is a glass dome design with a metal threaded base. Widely used in flashlights, equipment indicators, instrumentation lights, signal lights, warning lights, Interior lights, microscope lights, circuit experiments, etc.Are there any advantages of the product?The bulb has low power consumption and strong shock resistance and long service life. This set come with a storage box, helping you keep the bulbs neat and clean, easier to find them next time.How to use it?The side of the lamp holder is negative, and the bottom is positive; easy to install, remove the old bulb from the lamp holder and screw in the new one.What should I notice?Please provide a voltage that matches the rated voltage of the small bulb. If the working voltage is too high, the bulb is damaged easily; if the working voltage is too low, the bulb may not emit light.