Got these free with my machine… they were kind of a hassle and really ended up hurting my hands… I was probably doing 30-50 books per day. They worked good, it just became painful to do so many. We ended up getting an electric crimper (I think it is called a “finish at coil”?) and it is SO much easier. We still have the plier tool for a back-up, but if your usage calls for it, I def recommend a machine instead.