The black On-Stage Subwoofer Pole with M20 Thread is designed for pole-mount subwoofers and features all-steel shafts that telescope from 30 to 55”. The shafts are held tight with a friction locking knob backed up by a captive steel security pin to help avoid tilt and wobble. The lower shaft features 1.61” diameter steel tubing terminated with a zinc plated threaded lug. The upper shaft is sized to fit satellite speakers with standard 1-3/8" pole mounts.