Evenly distribute the sliced peppers among the mason jars.
In a large pan, combine all other ingredients and put over medium-high heat. While stirring, heat liquid until sugar dissolves and comes to a boil.
Pour the hot liquid into each of the mason jars leaving about a ¼" space from the top. Cover the mason jars with their lids and ring, then put them into the refrigerator. Let them sit at least overnight before eating.
These will last at least a month in the fridge, if not more.
Recipe by Learn by Cooking at https://www.learnbycooking.com/pickled-peppers/