Expandable Habitats' monthly sale for November is on their "Chewable Hangers" (or simply put skewers) - buy 3 medium or large Chewable Hangers or Toy Hangers and get 1 free.
Here they are on the website!
Now the medium or large refers to the size of the acrylic ball on the end of the skewer, not the actual length - the skewers themselves are available in short, medium or long (see the table on the website for exact measurements).
I purchased my skewers from EH last year when they had a similar sale. The birds currently each have a skewer filled with wood pieces and I think a few are almost due for a refill. Such an easy way to keep them occupied!
If you order, you have to mention that you saw the sale on their website (see here).