Gas Assist Speaker Pole with M20 Threaded Lower End, 38mm Pole & 35mm Adapter. The JBLPOLE-GA is the easiest speaker stand to use thanks to the internal pneumatic shock that literally raises the speaker for you. The stand’s internal shock easily raises speakers weighing 35 lbs and less with no effort from the user.

Features:
Raise and Lower the Speaker with Ease!
Strong and Easy-to-Use “Z” knob
Incredibly Sturdy Pole
M20 Threaded Pole Mount
Fits all subwoofers with standard M20 pole threading (JBL PRX, VRX, STX and SRX818)