The 100 foot roll of gray colored movie theater marquee lights have a 4 inch socket spacing. Note: The spacing on these marquee belts can vary 1/4 of an inch between the sockets as the spacing is estimated. Each socket has holes in the base to make installation easier. You will need a 4 circuit controller to power the light bulb displays and achieve various marquee lighting effects. This product can be field cut and modified using our accessories that we offer for custom marquee installations. The electrical wiring is rated for 15 amps of power and the sockets will fit any type of E27 base light bulb. We have many different types of E27 base light bulbs to choose from in our light bulb section of our website.