Here is our selection of 2 Pin Compact Fluorescent Lamps, ranging from 5 to 28 watts, all in varying color temperatures and base sizes. These bulbs use two pins combined with a block to secure the lamp into the socket. How you figure out the spacing between the pins is by looking at the name of the base. The number after the G or GX indicates how many millimeters between the pins. For example, a GX32d-2 has 32mm between pins, yet a G24d-3 has 24mm between the pins. Hopefully this should help better explain the different types of bases, but if you are ever confused or unsure then please do not hesitate to get in contact with our team of experts. They are waiting by to help you out with what ever you need!