Continuity Tester for Polarity Test is manufactured by MDR Electronics. MDR Electronics is an ISO 9001:2008 and ISO 14001:2008 certified company. MDR Electronics also supplies different types of audio/video, pro-audio cables, connectors & cords, electronic & computer/laptop accessories, cable organizers etc. Continuity Tester for Polarity Test allows user to check continuity of any cable. This Continuity Tester can check the polarity test for DC Supply up to 36VDC. This Tester has self test function.