I bought the large size recommended for parrots. It's way too thick for a Pionus to get his feet around. I'm still debating whether to put it in the cage or not. I don't think he's going to use it. I ordered the large also because it was the longest which I wanted.
We love chewy good prices, fast shipping, no fuss - no muss
he loves it! and I'm really hoping over time it will file his nails down