VK Roughlyte fixtures are for use on ceilings and canopies. VK units guard against moisture and debris in exterior applications for globe down mounting only . Not recommended for hazardous locations. 100W fixtures fit all 3.5 inch round and octagonal boxes and all 4 inch round boxes. Heat and shock resistant glass globe. Sockets are pre-wired with extra long 1/2 inch stripped leads. For 3/4 inch conduit, use VK series with VXL13 universal box. Guard not included.