Use a pastry bag coupler to easily change decorating tips. The Ateco Large Pastry Bag Coupler is made of plastic. Since 1905, Ateco has manufactured tools to help professionals as well as enthusiasts create extraordinary looking cakes, cookies and pastries. Ateco products begin with the finest materials, from metals to fabrics to plastic films and undergo testing for durability, reliability, and quality. They are made to last under the punishing conditions of restaurant and high-output commercial kitchens.