I bought these 4 packs because of the cheap price and they are 15 watt bulbs. They work great in wax melts. Most wax melters use 15W light bulbs. So be careful and read other ads as they try to sell you 7-8 watt screw type bulbs. They work for Christmas lights and night lights, but not decent wax melters. So far the new bulb has lasted a week, on all day and off at night.