Check the listing for details. On-Stage Airlift Speaker Sub Pole. Condition: New. Listed at 61.33 USD. Designed for easy, efficient one man operation, the On-Stage SS7748 Subwoofer Shaft with Lift Assist delivers universal subwoofer application with a first-to-market removable M20 lug in addition to standard 1 â " cup fitting. Providing 45 lb. of internal gas cylinder pneumatic lift assist and a 100 lb. weight capacity, the SS7748 features all steel shafts that telescope from 36.5" to 60" while employing a secure knob. The lower shaft has an M20 threaded lug for stability that can be removed to fit all 1 3/8" cups. .Designed for easy, efficient one man operation, the On-Stage SS7748 Subwoofer Shaft with Lift Assist delivers universal subwoofer application with a first-to-market removable M20 lug in addition to standard 1 â " cup fitting. Providing 45 lb. of internal gas cylinder pneumatic lift assist and a 100 lb. weight capacity, the SS7748 features all steel shafts that telescope from 36.5" to 60" while employing a secure knob. The lower shaft has an M20 threaded lug for stability that can be removed to fit all 1 3/8" cups. .