Amazon.com : ZEBRA GK420d Direct Thermal Desktop Monochrome Printer Print Width of 4 in USB Serial and Parallel Port Connectivity GK42-202510-000 : Label Makers : Office Products
Manual Zebra GK420D (page 97 of 102) (English)
GK420d Desktop Printer Support & Downloads | Zebra
Ask POSGuys: How to calibrate a Zebra label printer (GK420, GX240, GC420) - YouTube