UL approval for Canada and the USA. Flush mounting, DIN standard - H57. The H57 series hour meters are particularly shock-resistant and have a reduced installation depth. 7-digit, non-resettable hour meter with high shock resistance and data storage in case of a power failure. Small installation depth type H57 (48 x 48 mm). Other available voltage types: - 10-30 V DC, Order No. 297-1156 - 100-130 V (50 Hz), Order No. 297-1162 - 100-130 V (60 Hz), Order No. 915-5929 - 187-264 V (50 Hz), Order No. 297-1178. Applications: - General counting - Service interval measurement for: - Ventilators - Oxygen machines - Dialysis machines.