Rhin-O-Tuff's KF-50KB is a crimper for finishing coil-bound documents. It is not an actual binding machine but rather an accessory for binding. The crimper's job is to tuck in the ends of your coils once your documents are bound. Crimping ensures that the coil stays in place so your documents stay intact. The KF-50KB can be used as a stand-alone device or you may elect to attach it to one of Rhin-O-Tuff's binding machines or coil inserts. The crimper is compatible with the PC-248 binding machines as well as the HD-4170 and HD-e4100 coil inserters. However, if you choose to use it as a stand-alone tool, you must use the KB-50 crimping box as well. The diameter of your document's spine may be between 6 and 50 millimeters. Additionally, you have a choice of two tail lengths between 15 and 50 millimeters. Documents within these measurements do not require any extra tools, which increases this crimper's ease of use. One of the most popular features of Rhin-O-Tuff's KF-50KB crimper is its efficient and user-friendly handle, which is very comfortable to use. It will not make your wrist hurt even after putting together a large number of documents. This machine is extremely lightweight and easy to transport at only 3 lbs. It replaces the need for crimping pliers, which can be a pain to use for an extended period of time. Purchase your crimper today and start binding your documents!