Although these stands are made with lightweight aluminum construction and weigh only 5 lbs each, the Yamaha SS238B tripod stands can safely support up to 70 lbs. each. Dual locking height adjustment mechanisms clamp both the inner 1-3/8 inch.(35mm) tube and a permanently attached pin that slips through pre-punched holes. The speaker adapter plates allow stand-mounting of most loudspeaker brands. Sockets built into Yamaha's StagePas cabinets make them speaker-stand ready. The stands are sold as pairs and include a padded canvas carry bag.