Zebra RW 420, STD, Mag/Smart, Reader, Direct thermal, 203 x 203 DPI, 76 mm/sec Zebra RW 420, STD, Mag/Smart, Reader. Print technology: Direct thermal, Maximum resolution: 203 x 203 DPI, Print speed: 76 mm/sec. Bluetooth. Supported paper width: 51 - 105 mm