Pic with the slide up lid removed please.
Antenna (aerial in) will be Leftmost cable, and Power in will be on ANY of the outputs... so any of the three rooms those cables go to --- you fit a power supply to the cable in any one room you wish.
NB it looks size wise more like a 6-way to my eyeballs https://www.amazon.co.uk/Wolsey-WFAV-Variable-Masthead-Amplifier/dp/B00PKKTRBI/
with three spare ways.
Have a search in case the power box for it (the device with mains plug attached in the linked pic) has been left in a kitchen drawer or similar... Otherwise buy one!!
Antenna (aerial in) will be Leftmost cable, and Power in will be on ANY of the outputs... so any of the three rooms those cables go to --- you fit a power supply to the cable in any one room you wish.
NB it looks size wise more like a 6-way to my eyeballs https://www.amazon.co.uk/Wolsey-WFAV-Variable-Masthead-Amplifier/dp/B00PKKTRBI/
with three spare ways.
Have a search in case the power box for it (the device with mains plug attached in the linked pic) has been left in a kitchen drawer or similar... Otherwise buy one!!

