Limited time only. Dunlopillo Plus mattresses have innovative cooling technology mattress covers. The highly conductive properties of this clever fabric make you feel cool by drawing heat away from your body. Firmrest upgrades to Firmrest Plus. Celeste upgrades to Celeste Plus. Orchid upgrades to Orchid Plus. Diamond upgrades to Diamond Plus. Royal Sovereign upgrades to Royal Sovereign Plus. Millennium upgrades to Millennium Plus. Offer valid until Tuesday 30th November 2021. T&C’s apply.