Cable Port Brush Kit, Pack of 2 The Cable Port Brush Kit is used to cover the large cable knockouts in the cabinet’s top panel. Each kit includes two 3.9”W x 8.8”D (99 mm x 224 mm) brush-sealed grommets that snap into the opening on the top panel once the large 4.5”W x 9.0”D (114 mm x 228 mm) knockout is removed. The split design also allows the grommet to be temporarily removed to pass large three-phase 60 Amp PDU power plugs up to 4.5”W (114 mm) in diameter through the knockout when PDUs are added or removed. The standard top panel and accessory fan top panels have four large cable knockouts. The Vertical Exhaust Duct top panel has two large cable knockouts.