Bigger beds can harbor big dust mite populations if left unprotected. Our double bed encasements (for double mattress and double duvet) provide complete protection for a standard double bed. The double mattress encasement seals in dust mites and allergens, preventing them from disrupting your sleep. Add the matching double duvet encasement to keep your entire bedding set mite-free. With these covers in place, you and your partner can sleep comfortably knowing your double bed is safeguarded against dust mite allergens.