This metal purse frame is 4 3/4" x 1/2" There are some directions with the frame but basically you make a casing and put the arms through it, then put the cotter pin into the open end and bend it upward to close it. Note that when putting the two arms through the casings, you must start and push them through together. They can't go through the casings one at a time because the metal won't bend enough :-)
The cotter pin provides a loop for attaching a small chain or strap or other embellishment (beads, charms...)
These frames are also called squeeze frames, because they pop open when you squeeze the ends between your index and thumb. However this one is a bit long for that so I like to sew a tab or a charm to each side of the top middle to pull it open with. Let go and they pop closed.