A hose clamp Oetiker 13 x 15 is a type of clamp that is used to secure a hose to a fitting or nipple. It is made of a durable material, such as stainless steel or aluminum, and has a unique design that allows it to provide a tight and secure seal. The clamp has a diameter of 13mm and a clamping range of 13-15mm, which makes it suitable for hoses with an outer diameter of 13-15mm.