Fluke 27 II and 28 II digital multi-meters define a new standard for operating in harsh conditions with the features and accuracy to troubleshoot most electrical problems. Both meters have IP67 (waterproof and dustproof) rating, MSHA approvals, extended operating temperature range of -15 to 55 deg C (5 to 131 deg F, -40 deg C for up to 20 min) and 95% humidity and have been designed and tested to withstand a 3 m (10 ft) drop. The Fluke 20 series multi-meters are built to work in the toughest environments.