Replacement "push-in" style L.E.D. light bulb for the Singer Featherweight 221 and 222K as well as many other vintage Singer models. Better = brighter, truer, longer lasting and will not burn! This bulb will fit the following models: Singer 15, 99, 201, 221, 221J, 221K, 222K, 301, 306, 401, 403, 404, and 500. Fits perfectly in the Black and Tan and White Featherweights, too! A traditional incandescent light bulb has 850 LUX, whereas these new brighter bulbs illuminate with 2400 LUX. NEW AND IMPROVED! Each individual bulb contains 104 LEDs. Unlike the traditional incandescent sewing machine light bulbs, the LED bulb will not get hot or burn you. After testing it and leaving it on for several hours, it was only very warm to the touch, but not hot. These LED bulbs are designed to last for thousands upon thousands upon thousands of hours! That said, because they use a minimal amount of electricity and have extremely fine wiring, they sometimes can be more susceptible to failure with mini power surges and shorts common in vintage sewing machines. Therefore, keep your machine plugged into a surge protector at all times and we will warranty the bulb for up to 1 year. Our LED bulbs will fit many styles of old Singer Sewing Machines. So long as your old Singer takes the same style bulb as the Featherweight, this bulb will fit your machine. These LED bulbs can be a bit tricky to install. It is best to set your machine on end on a soft towel or blanket. Push and twist left to remove old bulb then push and twist right to install the new bulb. Be patient and if you have someone with smaller fingers, it may be a bit easier. Once you install it, it will be a lifetime before you have to install one again! (These bulbs will not work in a 220 volt machine, even if your machine is using a special converter box to enable it to plug into a US outlet.)