MFJ-4602 Window Antenna Feedthrough Panel with SO-239, Balanced Line, and Wire Antenna Connectors MFJs Weather-proof Antenna Feedthrough Panel mounts in your window sill. Lets you feed three coax-fed antennas, balanced line, random wire and ground without drilling through walls. Feedthrough Panel mounted to " x 3 " x 48" Western Red Cedar Plank. The customer cuts it down to their preferred size. The minimum would be 15 inches because the plate is at that point. Real Western Red Cedar wood is naturally resistant to rot, decay and insects -- lasts longer, maintenance-free. Pitch and resin free for a wide range of beautiful finishes or leave it in its naturally beautiful raw finish. Simply place in window sill and close window. Edges sealed by weather-stripping. Seals and insulates against all weather conditions. Gives years of trouble-free service.