Guess what this is?

I love walking along the water’s edge and seeing what kinds of shells I can find. I have jars filled with shells from all the beaches I’ve been lucky enough to visit. Hubby also keeps an eye out for me and this time he located the object below. We’ve been trying to figure out what it is and don’t really have a clue other than that it’s something that’s clearly been touched by human hands. So I’m reaching out to all of you to see if any of you can guess what this is!