The boxes and honeycomb inserts are made from USDA-approved chipboard, an eco-friendly, biodegradable material. All boxes are free of glue and/or any toxins that might be harmful to your pet bird. The box is heavy enough to maintain its configuration, but it must be torn apart in order to gain access to the contents. The bird chews or tears into the box to find food. After discovering the food source, it continues chewing or tearing through the honeycomb layers to continue accessing additional food.The box is housed in an impact-resistant, clear polycarbonate holding device. The box holders are available either in a vertical or in a horizontal configuration. A mounting bracket attaches the holding device to any cage with 3/8-inch to 1-1/4-inch bar spacing. Once the mounting bracket is installed, simply unsnap the box holder, and remove and replace the used box with a refill.