... . Spec.:30V,50V,75V...600V. For 450-450KV,use potential transformer...... Double Moving Iron AC Voltmeter1. Feature: W/O cover ... , 450V, 500V, 600V. For 450-450KV, meters can use potential transformer with secondary voltage 100V or 110V.5. Case: Non-combustile ... is flush mounting with bracket. ......More detailed products information or have further enquiry, welcome to contact us. Double Moving Iron AC ...