Protek 6800 80,000 Count Digital Multimeter with RS232C Interface Protek 6800 | TEquipment
Protek 506 Advanced digital 3-3/4 digit dual-display multimeter with RS-232 from Cole-Parmer
Protek 506 Digital Multimeter Protek 506 | TEquipment
Protek 6500 Digital Multimeter, 50,000 count and 50 segment bar graph backlit display, basic DC accuracy is ±0.03%, RS232 interface with software and cable, AC and (AC+DC) TRUE RMS measurement.(6500 Protek6500 Protek-6500 Protek 6500)