What is an 80×200 cm mattress?

An 80×200 cm mattress is a narrow single mattress with a width of 80 centimetres and a length of 200 centimetres. It is the narrowest standard size for children, teenagers, and adults. It's used both as a solo sleep mattress and, its most distinctive application, as one of two separate mattresses placed side by side in a 160×200 double bed.