It’s A CalCard and you should have one for your multi-function tester.

Review for CalCard

Works as advertised

Posted by Audipete (Amazon) on 2017-11-21 17:21:48

5/5

Posted by GAry Bowles (Amazon) on October 23, 2016

Review for CalCard

A simple and effective way to keep tracks of results on your tester

Posted by Audipete (Amazon) on 2017-11-21 17:21:48

5/5

Posted by stevefiler0 (eBay) on October 5, 2016

Review for CalCard

A great way of self testing my meters for reassuring accuracy.

Posted by Audipete (Amazon) on 2017-11-21 17:21:48

5/5

Posted by Gary (Supplier) on January 1, 2014

Review for CalCard

used these cards for years found them to be very accurate ideal for onsite checks.Brought a new one as original one was stolen

Posted by Audipete (Amazon) on 2017-11-21 17:21:48

CalCard® from TestCal