The Busy Barrel below is a 2.5" diameter barrel shaped vessel with six wing nuts that can be unscrewed. Two sides of the barrel then fall away to reveal a treat inside or simply to keep birds busy opening it up. There are also two wing nuts that unscrew on the sides. Constructed of solid aluminum the Busy Barrel is designed to last a lifetime. Birds love the challenge and the clanking noises it makes when coming apart. The wing nuts will not fall off as the threaded rods have been hammered so the can't come off and you don't have to "forage" around the bottom of the cage floor to find them!