That appears to be a generic pole storage clip, like the one shown in the link, not a Fortress Anchor part.
https://www.basspro.com/shop/en/bass-pro-shops-pole-storage-clips?hvarAID=shopping_googleproductextensions&ds_e=GOOGLE&ds_c=Shop%7CBPS%7CTopPerformers%7CBoating&gclid=CjwKCAjw_tWRBhAwEiwALxFPoYl437r8T4oH1C7r1LO_nravWUP31qn8r8OgYMP1558Q1xckN5g4ARoCbScQAvD_BwE&gclsrc=aw.ds
