To use this accessory, start by removing the thick, durable, plastic card piece from the strap. Then remove your phone case and place the card through the charging slot of your case. Put your case back on, reattach the strap, and you're done! So easy and so cute! These acrylic straps feature a marbled effect throughout them, adding even more beautiful details to the look. They are perfectfor concerts, a day at the fair, amusement parks, a night out with your friends, & more!