This document describes several industrial desktop label printers from Citizen. It summarizes the key features and specifications of the CLP 521, CLP 521Z, CLP 621, CLP 621Z, CLP 631 and CLP 631Z models. The printers feature durable metal mechanisms, easy media loading, internal power supplies, and print resolutions from 203 to 300 dpi. They are suitable for printing labels, barcodes, logos and other materials.