Our acrylic inserts are turned one at a time in North America by our friend Tom. Each one is hand fit to our Atlas 7-9wt hardware and can be ordered three finishes. The insert you see in the picture is the one you will receive. We have assigned each insert a unique serial number. The bore on the 7-9wt. inserts is: 0.469" (8.3mm). Each seat comes with a cork check to mount a fighting butt or lower grip.