Philmore Deluxe High Isolation 3-Way Coaxial A/B Switch Fully Shielded with Zinc Die Cast Inner Case Selects 75 OHM video devices for viewing on TV set. Switch between directional antennas; cable and outside TV antenna; computer inputs, etc. Zinc die cast inner case offers complete internal protection. Fully shielded with low conductivity gaskets to eliminate interference between signals - No bleeding - no station interference - no picture loss. Eliminates interference between signals because of a high isolation of 950-890mHz..