Cache In Trash Out ® events are a great way to give back to the environment in which we play our game. Fill as many of these CITO Trash Bags as possible when you help clean up parks, forest trails, and other cache friendly places throughout the world. These new smaller 20" x 20" x 4" trash bags and are made of 2 ml plastic film. They are bright yellow so we can show the muggles that we are out there doing our part for the environment. This high visibility is also a safety feature if you happen to be doing CITO along a roadside.