I've been a decades-long user of Power Probe products and frankly have never had a problem with reliability or performance.
Have seven different Power Probe Kits (including ECT 3000s, 2000s, "Hook", Power Probe 3s). Picked up a Power Probe IV approx a year ago and it's served me well and has now become my "go to" Fuel Injector Diagnostic Tool --- vice noid lights or hauling out the laptop, PICO, etc.
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