The Prym shoulder strap holders prevent the slipping of vest or bra straps when wearing sleeveless clothing. They are sewn into the garment in the shoulder area, passing the straps through the loop that is closed with the snap button. This allows even wider straps to be held perfectly in place. The Prym shoulder strap holders are made of 100% polyester and feature a stainless steel brass snap button. They are available in white and black and on a card with 4 pieces and can be washed up to 40 degrees.