Say goodbye to Cage Nuts and start using the faster, easier way to mount your equipment in 19" racks. The revolutionary new RackstudsTM are a universal replacement for the common cage nut. If you use cage nuts to mount IT, Pro A/V, Security or Telecommunications equipment in 19" racks, you're going to love RackstudsTM. Suitable for most* 19" racks with square punched vertical rails, RackstudsTM go in from the front and provide you with a place to hang your equipment while spinning on the lock nut. This makes mounting even heavy equipment much easier; even if you're on your own. They are easier, faster and safer than cage nuts and very strong. *Ensure your rail thickness is between 2.2mm/0.086" and 2.7mm/0.106". Use RSL100 if rails are <2.2mm/0.086". These new DARK blue Rackstuds suit Chatsworth, Great Lakes, Legrand and others with thicker vertical rails and were upgraded Jan 2016 to make them more compliant with rails at the fringe of the max width.