The removable three-ring adaptor is a handy option some times. It comes installed, and attaches using the cords that are already in your folder. You can add one, or two ring adaptors – you might want to hold the first half of a concert program in one, and have the other half ready in your second adaptor ready to quickly swap in at intermission, so you can spend the time chatting about the performance instead of fussing with paper. People who sing in more than one choir can also keep music separate. Attaching the adaptor to the folder with the cords adds security but is not required, you can just drop an adaptor with your set of music into your folder and be ready to go.