Standard Couplers: these white couplers are 3cm long and the base diameter is 2.5cm, suitable for standard size icing tips Applicable area: the standard coupler fits all standard size decorating bags and tips, helps you change tips without wasting bags or frosting unnecessarily Easy to use: cut a small hole in the corner of the bag, insert this plastic coupler, then attach the tip and screw the ring, when you are done, remove the tip and coupler, wash them clean Durable and practical: the piping tip couplers are made of quality plastic, with sturdy construction, allow you to decorate cake and cookies conveniently and quickly Quantity: 12 x cake decorating couplers, enough for different uses, you can change similar sizes of tips without emptying the contents of the decorating bag