Synthetic duvet has a siliconized synthetic fiber. At 60 degrees washable without loss of volume. Antibacterial by the addition of silver wire. Thermal class 4 with 225 grams per m2 filling which is ideal for the summer and heat Class 3 with a filling weight of 300 grams m2. The four seasons duvet consists of the two thermal classes. The comforters are connect with each other through a button system.