The 17390517 is a Curtis 700 Series solid state digital hour meter designed to reliably track elapsed time across a wide range of industrial and commercial applications. It features a 6-digit LCD display with 5mm or 7mm high digits and a 6 o'clock viewing angle, capable of measuring up to 99,999.9 hours with 0.1% accuracy. The unit operates across an extended temperature range of -40°C to +85°C and maintains data retention for 25+ years without power through EEPROM memory technology. With robust mechanical specifications including 55g shock resistance and 20g vibration tolerance per SAE J 1378, combined with 95% humidity tolerance, this hour meter is well-suited for scheduled maintenance tracking, warranty documentation, and equipment leasing applications in medical devices, transport vehicles, and industrial equipment.