Mighty Super J cups are sold in pairs, and offer support for the barbell on a rig or a rack, in-between the reps. The laser cut steel is covered on both sides with plastic. At the back of the supports, to protect the pillars from getting scratched. While at the front they offer protection for the bars knurling marks. The J cups are easy to move and can quickly be adjusted to the needed height, depending on the exercises we perform and our height.This series is compatible only with Mighty pillars.