Dunlopillo has achieved a Which? Best Buy Award for their Royal Sovereign mattress for the second year running. Which? is the largest consumer body in the UK, known for testing household products to help their subscribers make informed purchasing decisions. The Dunlopillo Royal Sovereign mattress retained its Which? Best Buy Award this year after receiving 72% in its test score on categories such as brand comfort rating, body support, breathability and overall durability. Made from 100% pure Dunlopillo latex with.