Royal 30137S Time Pilot Vetro Electronic Time Clock, Charcoal; Up to 500 Employees; Includes Time 10 iButtons, AC Adapter and PC based Software Identifies employees by their iButton or by a 4-digit code entered on the sleek, blue backlit keypad Automatic tracking and calculation of regular time and overtime Weekly, bi-weekly, semi-monthly, monthly & custom pay periods Calculates worked hours (including overtime, holidays, etc.) in just seconds Works with top payroll software and services, including Quickbooks, ADP, and Paychex