Promise ring

Have you guys bought your s/o a promise ring? Is that a thing lol ? My bf/babys father got me a promise ring last mothers day. Im so obsessed with it and He’s jokingly told me why i don’t get him one. He tells me so much that im starting to think he wants one lol. We want to get married but we don’t have the money to atm. So if i was to get him one i want to get him a nice one. If you guys have gotten him one , please drop a picture so i can get ideas :)❤️ this is my beautiful ringg