Washer rings way too small
I bought the 17 size for my Timneh African Grey and the perch itself (I got the green) is nice and heavy and love the quality, however the washer rings are way too small and go right between the bars of his cage. The chunkiness of the perch is about the size of the rest of his which he likes but the length is quite short so I would say go smaller for small birds and bigger for larger parrots. Be prepared to have to go buy bigger washer rings or hope you have some on hand like I did from old perches.