Brah! Extenders simply make life a little more comfortable. Whether you're inbetween sizes or experiencing maternity weight gain, Brah! Extenders give you the breathing room you need to tackle life's other challenges. They simply attach to the hooks on your bra band, giving you a little more breathing room and extending the life of your favorite bra. Ultra thin, soft microfiber with nylon-coated hooks. The measurement between hooks is 3/8 inch on the 2-hook NARROW, 1/2 inch on the 2-hook and 3/4 inch on the 3-hook.