These top-of-the-line boom stands feature a variable, piston-type air suspension system to ensure microphone protection. Model SB-36W is equipped with silent-motion, ball-bearing swivel casters of hard rubber for friction-free and vibration-absorbing mobility.Two-piece horizontal boom assembly is 7/8" dia. cold rolled steel with a heavy-duty, die-cast, gyromatic swivel and an adjustable 6-lb. counterweight for precise and secure orientation. Tubing terminates with an adjustable mic holder swivel with standard 5/8" - 27 thread to accept all microphones, holders, and adapters.Vertical tube assembly is manufactured of 1-1/8" and 7/8" chrome-plated cold rolled steel and includes the wearproof Atlas Sound grip-action clutch for easy adjustment and positive locking. Model SB-36W includes wheels for a height span of 49" to 73". Triangular cast metal base with edge-concentrated weight distribution offers extra stability and is finished in ebony epoxy with a chrome shell.