Easton G nocks fit this size of nock insert. They come in two sizes, S and L, depending on the diameter of your string serving. Mostly, people shoot small diameter strings with 1716’s, because they are shot out of lower poundage bows, so that would be the S size. This is a common nock that is used with many other arrows, such as Victory VAP’s, etc., and are made by many other companies, such as Bohning, perhaps for a lower price. Every company’s designation is different, so you have to figure it out by the diameter of the part of the nock that fits into the insert.