Porcelynne Clear Plastic Bra/Headband Replacement Strap Rings - 3/8" or 10mm Opening - 50 Pairs Clear plastic rings that measure 3/8" or 10mm on the interior and are in the shape of a 0. Check the seller's other products for slides and hooks. Each pair contains 2 pieces. Used on bra straps, tank top straps and headbands. Bra/Headband strap hardware ideal for replacement parts or custom bra making. Can be used to make adjustable straps of any kind.