Where can I get flip flop relays in UK?

[forknowledge]

I want to give the flip flop method a try but cant even get my hands on the relay in UK, can anyone recommend a store please?

 

[4.D.]

I would contact a commercial Electrical Supplier. Ask for a "square d"

should have similar specs to this

 

[Buddy Flowers]

just turn the one room on when the other goes off?