The J-Rak from Radial Engineering is a 2U rack shelf that allows as many as eight Radial direct boxes to be rack mounted. These can face forward (input at front,) or backward (XLRs at front,) be active or passive and in any combination, depending on the system designer's preference. The J-Rak also accommodates the Radial X-amp re-amplifying device.

Installation of the individual units is simple. It requires only the taking off of the "Book-End" cover, attaching a supplied sleeve to the unit, which is then in turn screwed to the top of the rack.