Braza Bra Back Corset Extender-For 10 to 13 Hooks-Black Expands any 10 through 13 hook corset for extra breathing room. Can be used on 10, 11, 12 and 13 hook corsets. To fit, simply cut on the heat seal line for a 'no fray' result. Color: Black. Material: Nylon. Measures 9.5" high x 2.5" wide.