The HD J-cups are a "sandwich-style" set up designed to keep the shaft of your bar from coming in contact with any metal portion of the J-cup.  Beefier construction allows for greater load capacity and safety compared to traditional bent-steel style j-cups. 

Specs:

Pin size 1"

Tubing size: 60mm, 65mm, 75mm 

60mm: Basic Power Rack (Before 2022)

65mm: ALL MODELS BEFORE 2022 Wall Rig, Folding Wall Rig, Deluxe Power Rack, 6FT Squat Rack, 7Ft Squat Rack, Deluxe Power Rack

75mm: ALL CURRENT MODELS (AFTER 2022) Commercial Racking Systems, Wall Rigs, Folding Wall Rigs, Deluxe Power Rack, Power Rack, Deluxe Squat Rack, 7ft Squat Rack