PME 12\" Disposable Piping Bags - Pack of 12 These disposable icing bags are ideal for use with a wide range of icing tubes. Use with or without a coupler - full easy instructions for using the coupler are included on the box. Use of a coupler enables you to easily change the tube from one design to another without changing the bag. The contents can be easily identified through the clear, durable plastic. Ideal for use when piping with royal icing, buttercream, chocolate, meringue, whipped cream, mashed potato and other food products. These bags may be used in the microwave.