In order to choose the size of your mattress topper, you must know the size of your mattress, both must be equal. Therefore a 180x200cm mattress topper should be positioned on a 180x200cm mattress. Check your measurements ! Synthetic mattress toppers are fitted with elastic hooks, while down comforters are kept alone because of their greater weight. If you choose a 6cm thick natural fluff mattress topper, consider checking the size of your bed sheets to make sure they fit the thickness of the mattress and the mattress topper. The mattress topper 180x200 cm is a supplement of comfort to a firm or medium mattress, it will assure you an unsurpassed softness.It is the ideal companion of a mattress for a good maintenance. All those who have tested our mattress pad in a luxury hotel with Dumas Paris products recognize that it is incomparable ! However it will not give a second life to your mattress ... For a special mattress topper size, we can make a tailor-made mattress topper for you within 10 days. However, custom-made mattress toppers are neither taken back or exchanged. Finally, it is important to know that the natural down mattress is not washable in a traditional machine or in the dryer. That's why it should be protected like a mattress, with the protective cover that we offer.