This RF Modulation has a range of RF Modulators from HDMI, UHF, etc. RF Modulation is used to convert and send AV inputs like CCTV DVRs, Satellite Receivers etc over coax cable. HDMI Modulators send a HD picture over coax and is commonly used in Hotels, BnBs and similar systems. They are commonly used to be able to view your CCTV DVR in all rooms of the house. The fact they can be used in conjunction with the Saorview signal opens up a lot of opportunities for multi-channel systems.