Where can one purchase a Super King mattress?

Mattress sizes vary based on where you are buying them. If you are shopping the in UK for a mattress, then the term 'Super King' is used to refer to the largest size mattress you can buy (72 in. x 78 in.). So in order to purchase a mattress of this size, you will likely need to shop on a UK website or in one of their mattress stores. Some of the UK mattress companies that make the 'super king' size are: Silentnight, Rest Assured and Layezee. Their company websites would be a good place to start your search.