This is a good tester, but you need a battery (1-AAA) for power, whereas the 29-1050 doesn't need a battery to operate. Verdict: this one is good, but the 29-1050 is "not dependent" on battery power to operate and is a little less expensive.
I purchased this because I thought I would like the design & smaller size a bit better than Part No. 29-1050. Unfortunately, the battery test results don't agree with those from the 29-1050, which in my opinion is much more accurate. Every new alkaline battery I test (D, C, AA & AAA) only indicates 1/2 "Good" on this unit, whereas they all indicate full "Good" on the two 29-1050's I own. In addition, fully charged NIMH batteries, which indicate full "Good" on the 29-1050, only register as "Weak" on this unit (28-12547). The 29-1050 has a separate scale for rechargeable batteries, but this one doesn't (which is probably why they register as "Weak.") The web listing does not state whether or not this device tests batteries "under load conditions."My recommendation -- get the MW222 (Part # 29-1050) for more accurate battery test results, especially when testing rechargeable batteries.
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I have dealt with MCM Electronics a number of times and have been more than satisfied.