Porcelynne White Nylon Coated Metal Replacement Bra Strap Slide - 3/4" (18mm) Opening - 50 Pairs (100 Pieces) White Nylon Coated Metal hardware. Used on bra straps, tank top straps and headbands. Hardware has an 18mm opening, which is 1mm smaller than 3/4". Accommodates 18mm wide elastic. Replacement hardware for straps. Matching elastic also available by Porcelynne