The PF at the end of this tools name hints at the purpose driven design of this Picture Frame tool. A narrow crown staple can be partially driven into the frame so that the part of the staple still "standing proud" acts in many ways like a Flex Tab. Yet, is drives a conventional and readily available 3/16" X 21 gauge 97 series type of staple that will neatly secure glass, artwork and backing board into frames. A tiny tool still infused with the necessary strength to serve industrial needs.