The Brady 149043 is a 120 mm i7100 Platen Roller and it's used for Industrial Label Printers, and it's Green synthetic rubber roller material that is recommended for high print accuracy on small and large labels and it's using a roller of similar width as the media reduces wrinkling and extends print head life. It is used with media width up to 120 mm wide and used for the narrowest roller that covers the media width, and the narrowest ribbon that covers both media and roller Rollers are easily changed out using the onboard hex key tool that ships with the printer, clean rollers often with IPA cleaning swabs and replaces worn rollers to prevent damage to the print head.