Modular air containment system is designed to maximize cooling predictability, capacity, and efficiency.This Rear Assembly is designed for NetShelter SX 42U 600mm Wide, and includes: Left side plenum - 1; Right side plenum - 1; Rear Lexan insert for non-locking door - 1; Rear insert assembly for locking door - 1; Rear insert retainer for non-locking door - 1; Rear insert retainer for locking door - 2; Top/bottom plenum - 2; M4 . 12-mm pan-head screws - 1; 6-mm snap rivet - 6; M6 flanged hex nut - 6; Grounding wire, female - 2; Grounding wire, male - 2.