The little translucent balls with cutouts are perfect for tucking in sunflower seeds, and my budgie now ignores his old mirror toy completely. Hanging it took two seconds and it's held up fine to daily beak abuse.
My cockatiel spends ages trying to fish seeds out of the cutouts on those translucent balls—it's the first toy that's held her attention for more than a day. The chain hangs nice and sturdy from the top of the cage, and I love that I can just stuff a treat in there to keep her busy while I'm at work