Casio Mens E-Data-Bank Digital Casual Quartz Watch (Imported) CA-506C-5A Imported 8-Digit Calculator (Constants for addition, subtraction, multiplication and division ) Water Resistant, Dual Time, Daily Alarm Hourly Time Signal, Auto Calendar (pre-programmed until the year 2079) Accuracy: +/-15 seconds per month, Battery CR2016 Approx. battery life: 5 years, Module 437, Size of case/total weight: 42.0 x 33.0 x 7.0mm / 29g