Features Made of food grade silicone - safe to use with Smooth interior - easy to squeeze and wash with Rough exterior - anti-slip good grip Easy to Clean & Reusable The cake piping bags smooth inner surface is easy squeezing and washing. Food-grade material makes it reusable many times. Icing pastry bag can be easily trimmed and work with any decorating couplers and tips. How to Use Put the coupler in pastry bags cut the extra parts, Do not cut too much or your icing coupler may slip out the bottom. lace the tip on the coupler and use the coupler ring to secure the tip to the outside of the icing bags. Tighten the tip into the coupler. use a squeegee or spoon to pick up the filling and insert it into the icing bags. Fill the bag in just 2/3 to 3/7.S lowly apply pressure to the bag through the hand at the top of the frosting bags until the filler begins to flow out