I'm trying to buy more duplicate arrow nocks for my wood arrows, I don't know what kind they are. I will try to post a picture later. On the side they say the size, 9/32. I know this may be a common identifier.
The fact that 9/32 is printed on the side may help. Not every nock manufacturer has the size on their nocks. The Bohning T nock comes in 9/32 with the size molded into it.