A half pinecone attached to a piece of hardwood fence paling (untreated and non-toxic to birds) with a little side perch for easy foraging. It comes with two stainless steel hooks on the back to hang from any cage surface. Simply pop a few nut treats into the opened pod cases and let your bird wander up and down trying to find every little morsel.
 
Please mention what size bird you have (small, medium or large) as pine cone size varies.