On-Stage Adjustable Subwoofer Attachment Shaft (SS7745) Our SS7745 Adjustable Subwoofer Attachment Shaft mounts to the top of a sub cabinet and supports a speaker with a standard pole-mount socket without using a separate floor stand. The shaft s height adjusts to accommodate a variety of applications and locks in place to ensure reliable positioning. Product Highlights Height settings are reinforced with a locking pin to ensure reliable speaker support Mounts to the top of a subwoofer and holds a PA speaker weighing up to 80 lb Steel construction delivers stability for precise dependable speaker placement Height adjusts 31.63 –55 to adapt to a wide range of venues and applications