On-Stage SG5000 Glider Universal Subwoofer Roller/GliderAdd casters to your subwoofer without the need for drilling holes or making modifications with the On Stage SG5000 Sub Glider, a universal subwoofer and speaker platform with six 3" casters (2 locking). The unit offers adjustable width and depth, ensuring your subwoofer locks in tightly for safe and stable operation during transport and on the stage, while anchor points allow you to use optional straps to further secure the sub to the frame. Made for