These receivers are for the new Widex Rechargeable Moment and Sheer hearing aids. Size: They come in sizes 0, 1, 2, 3, and 4 with 0 being the shortest and 4 being the longest. Power: There are two powers, M for mild-moderate hearing loss, and P for moderate to severe hearing loss. Your current receiver should specify the power and size of the silver part that goes in your ear. Sometimes it rubs off, if you are unsur,e you can always send us a picture or check with your audiologist!
