Videopath / Dish Network / Bell ExpressVu Legacy SW21 Switch. Use this device to hook up 2 inputs (up to 3 orbital satellite locations) to one receiver. The legacy SW21 switch combines two legacy dual LNBF's into one coax line. SW-21 Switch for Dish Networks Dish 500 System or two dish system. Permits voltage switching between 2 satellites. For a dual receiver system 2 of these are required.