These PL-T triple-tube plug-in light bulbs have a wedge-style base with four pins. They are compatible with electronic-ballast light fixtures with a matching socket. PL-T triple-tube plug-in light bulbs have a maximum overall length of 7 in. They have a larger diameter and provide more light than PL-S short twin-tube plug-in light bulbs. The bulbs have bases with two or four pins that plug into matching sockets on lighting fixtures. The design of the bulbs' bases ensures the bulbs will only install into lighting fixtures that the bulbs are compatible with. Compact fluorescent (CFL) and fluorescent versions of these bulbs consist of three short tubes.
LED versions of these bulbs are rectangular. PL-T triple-tube plug-in light bulbs are used in corridor light fixtures and office light fixtures. Plug-In CFL Bulb, 3000K, 26W, 17, 000 hr