18" internal purse frame. Upper right in picture shows flex frame hinged and open. This frame comes to you hinged. To insert frame into purse, tote or bag: unhinge both ends. Slide each piece through its prospective casing that you have made and rehinge. To unhinge: use pliers to pinch end of frame to release pressure and work the pin out. Do the opposite to rehinge. Frames can be removed for bag to be laundered.