Light bulb with threaded, screw style base for use with 6-volt battery. Bulb socket and/or holder sold separately. Threaded bases are 9mm wide, bulbs are 22mm long. Product photo is enlarge to show detail.
Review by Jay
These bulbs and the sockets we ordered with them were excellent for the chemistry project my kids used them for and very affordable.
Great for the lab, but wish they had lasted a few more experiments.
Review by Ellen
They were the perfect size for what I needed; wish they had lasted through the entire lab sequence. Also, please include the suggested voltage of batteries -- I had to play around a lot with this to get bright enough light.