The LDDF is a dual-door frame used to separate and secure equipment in a single rack installation. It can be used to mount a single short door (leaving part of the rack open), two short doors (keyed the same), or two short doors (keyed differently). Suitable for Lowell rack series noted below, the 1"D frame is factory-installed when ordered with a rack or it can be field-installed without drilling or removing pre-wired equipment. It face-mounts using (4) 10-32 x 5/8" hex washer-head machine screws (included) to top and bottom nutserts on rack (typically used to mount door hinges). Security Bracket (included) mounts to top of lower door, completing the dual-door system. The bracket projects into the rack to within 1/4" of mounting rails to secure contents of lower section when top door is open. Bracket is factory-installed when frame is ordered with rack. It can also be field-installed with two screws. Bracket can be field-changed to bottom of upper door or not used at all.