Ateco Standard Metal Coupler 405 Perfect for piping meringues, cookie dough, icings and for filling with centre fills eg caramel and other treats. Stainless steel coupler is designed for use with standard decorating and filling tips. Good for heavy duty. HEAVY DUTY Standard Coupler Metal allow you to interchange standard tubes and other small tubes without having to empty the contents of the decorating bag. Perfect for enhancing dessert presentation Great for creating decorative ideas