Extech has issued a recall of EX650, EX655, MA160, MA61, MA63 series clamp meters made in 2017.
http://www.extech.com/display/?id=16536"This recall stems from consumer reports that the clamp meter’s input terminal screws are loosening. The loosened screws can create an open circuit at the test lead input jack of the meter, causing the meters to give inaccurate voltage readings. An incorrect reading can cause the user to falsely believe that the electrical power of the test subject is low or off, in turn, posing an electrocution hazard."
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"The affected clamp meters units were sold during the period of January 2016 to April 2017, and were distributed under the Extech brand. The following model numbers are affected by the recall: EX650, EX655, MA160, MA61, MA63. Serial numbers in the following format are included in the recall: R15XXXXXXX to R17XXXXXXX."