This is an indoor booster made by SONY for TVs (terrestrial digital & BS). It has four outputs, so it's suitable for people using multiple TVs or video devices. I haven't confirmed whether it supports BS-4K, but I think it should be fine since the antenna and coaxial cable are the same as for regular BS broadcasts. I don't think it will work for BS-8K. It was purchased a while ago, but operation is unconfirmed.