The Penn Elcom R1268/1UK-PBSO is a 1U 19" open-style rack panel featuring an integrated cable access slot and dust-resistant brushes. Unlike traditional fully enclosed brush panels, the "O" in the part number designates an open-sided construction. This specialized shape lets you slide or route cables into the brush slot horizontally without needing to un-terminate or disconnect the cable ends first. The built-in heavy-duty brush strip acts as a barrier that seals empty space to block thermal recycling. It forces hot air out and traps cool air in, while comfortably accommodating highly dense wiring. The synthetic bristles tightly hug passing wires, minimizing airborne dust intake inside sensitive AV, broadcast, or network enclosure installations.