Martindale-VI13700-Voltage-Indicator-Martindale-MARVI13700-2-P-The-Martindale-PD690-is-a-700V-AC-proving-device-designed-to-enable-voltage-indicators-to-be-fully-checked-in-compliance-with-Health-&-Safety-recommendations-Using-a-voltage-indicator-without-first-proving-it-is-working-correctly-could-prove-fatal-P-P-This-device-is-designed-for-indicators-with-230V-&-415-440V-AC-detection-ranges-such-as-the-Martindale-VI13700-The-proving-unit-is-one-of-the-few-designs-to-check-indic