If your bra has 2 hooks and eyes 1 1/4" apart then this 2 Hook Narrow bra extender is the one you need. If you have 2 hook bras, some with the hooks closer and some with the hooks farther apart, you should purchase a package of each 2 Hook extenders since they are not interchangeable. There are 4 positions making it easy to adjust your back band to your perfect support and comfort level. Adds up to 3 inches to your bra's back band.