What is a 20x72 mattress called?

A mattress measuring 20x72 inches is typically referred to as a "cot" or "crib" mattress, often used in smaller beds or for specific purposes like camping. It may also be categorized as a "twin" size for certain types of bedding arrangements. However, it's important to note that standard twin mattresses usually measure 38x75 inches, so this size is less common.