RM3U1918SBK is a 3U rack-mounted instrument enclosure designed for both rack and desktop applications. It features a robust extruded aluminum construction with a textured black powder coat finish, providing durability and professional appearance. The enclosure measures 5.25 inches in height, 16.60 inches in width, and 18.00 inches in depth, with a 3U rack unit configuration and includes 19-inch mounting flanges for standard rack integration. The knockdown design ships unassembled for easy handling and shipping protection, and includes top, bottom, sides, self-adhesive rubber feet, one pair of rack mount brackets, and all assembly hardware. The front and rear panels are interchangeable, and the enclosure accepts an adjustable rear bracket (RM3U18BRKT, sold separately) for deeper mounting configurations. This enclosure is ideal for housing electronic instruments, control systems, and audio/video equipment in professional installations where compact, reliable, and aesthetically finished rack-mount solutions are required.