MARTINDALE PD690SX 50V/120V/230V/400V/690V AC Proving Unit with CALCHECK
The PD690SX has all the capabilities of the standard PD690S proving unit plus a unique CALCHECK feature for verifying the performance of installation testers and 5 stepped voltage thresholds matched to common two pole tester thresholds.
£79.95
(£95.94 inc VAT)