What kind of electronic calculators do you use in your dispensers? What are the general specs?

Currently we are using and manufacturing 2 type of electronics, S4 Pro-B and Pro-C4 which is based on S4 Pro-B but improved hardware version. General specs of both electronics are :

Support up to 4 nozzle,4 display,4 electromechanic counter at the same time.
Includes WYN-Dart and S4-Dart protocols over Current Loop communication.
Can work with 110V or 220V AC according to PSU selection.
Ability to make electonic W&M calibration and Automatic Temperature Compensation(ATC).
Error reporting and history.
Manufacturer, Serviceman, Pump Salesman and Station Administrator level password protection for menus.
Easy operations with Alfa-Numeric keyboard nad 2*16 Dotmatrix.
Mutiple Language support. (English and Turkish are default)

For more information please refer Pro-C4 Datasheet