The Wavemaster XXL has a locking nut made of hard plastic that sits at the base of the XXL punching bag. Once the bag is assembled this piece sits flat on the floor. The bag is slid through the hole on the base and tightened clockwise into this lock nut. Turn counter clockwise to remove the bag. This locking nut is only compatible with the Wavemaster XXL and not the 2XL. The dimensions are: 14" x 11" x 3-1/2" Inner Diameter of 6.
