Promise Rings... For men??

This is probably a really weird question, but whatevs, I'm a weird lady.

Anyways, I've been with my wonderful boyfriend for almost a year now. We met last year while I was in a relationship with someone else. After I met him I soon realized how bad my ex was for me (23 and going nowhere, while I was 19 and almost half way done my degree), and how good he was for me (21, University, Dean's honour list and doing co-op periods for work experience).

Since then, things have been really good. Usually around this time I start to doubt my relationship with someone, but this time I haven't. We compliment each other in many different ways and bring things into the relationship that allow us to grow individually as well as a couple. We work well together and apart, we are also very supportive of each other's goals and dreams. He also listens to me. I've had past boyfriends hear me say things and not listen, or they do listen but don't follow through. He did by taking note that I told him a guy has never gotten me flowers. So what does he do on Valentine's? Gets me a bouquet of the prettiest pink roses. He is the first guy I have dreamed of marrying and repeatedly have pregnancy dreams that feature him as the father (of course we aren't ready for that yet 🙊)

And this is where my question comes in... Since our one year is coming up soon, I want to get him something that's nice and comes from the heart. Particularly a promise ring. I know that's really "high school", but we're only in our early 20s and not ready to think seriously about marriage yet. I want to give him a ring so he knows that I am not going back on my promise that I will work hard for him, our love and our relationship. But promise rings for men don't exist, and I have never seen him wear jewellery. He doesn't own any either... How should I ask him about it without giving it away? Would I be better off getting him something else?