This is a nice AP refractor focuser with 3.1" and 3.4" OD tube flange rings. The outer one unthreads from the smaller one. It comes with 3 very large stainless steel screws. As seen in the photo, a 1.25" adpter is included as well. As with any AP product, this one is well machined and in overall good used condition. The price includes shipping in conus.
thanks for looking