Not a button hook, I have some of those and that is not what it looks like. Not a latch hook cause they don't have the extra spring thing on it. Not a knitting machine needle (I have one) because that wouldn't have a handle or that spring on it, and it would have to have a raised part to catch the carriage. I think it might have been used like a crochet hook, someone once gave me a device, more modern than that one looks that you could use like a crochet hook and it had a plastic part half way down that controlled how much yarn you would pull by controlling how far you were able to go into the stitch.