Creating double loop wire or plastic coil bound documents is fast and easy with the Akiles DuoMac 421/431 Binding Machine. For plastic coil bound documents, simply punch your sheets and manually insert the coil. After the coil is inserted, use the coil crimp tool, included with the DuoMac, to crimp the ends of the coil. For wire bound documents, simply utilize the other die set and integrated wire closer. With the power of two machines in one, binding has never been easier!