Unacceptable device, unaceptable tactics of customer service, no refund
1. The Fnirsi Oscilloscope 2D15P does not provide the promoted 1M memory function. The button to change the memory depth shows no effect. It has no influence on the sampling rate and also no zoom is offered. 2. The promoted bandwidth is not available for signals with a fundamental below several MHz. Means in many digital signals and in common switch mode power circuits you cannot examine the correct sloping or see undesired ringing of the edges. 3. The probes are low quality, in my case they are introducing a 5% error in signal size. While point 3 is just a minor issue - points 1 & 2 are limiting the usability of this scope to the same level like any cheapest 20MHz scope could serve. Customer service is either not answering or just going for annoying delay tactics for three weeks now. They did not send me an adress information for sending it back, no offer for refund. They just let you wait until you give up. My gerneral advice: Do not buy Fnirsi.