Lamp replacement made easier, faster and safer with one-touch twist & lock base. Metal Halide and Tungsten Halogen lamps available "Metal Halide lamps" have eXtreme Seal (XS) technology allowing 450ºC at the pinch seal Two Base Sizes: PGJX50 & PGJX28 Interchangeable with other PGJX50 and PGJX28 lamps and sockets due to universal base design Lok-it lamps used with Lok-it sockets make for an optimized system solution