Update: When I returned the units via ÍøÆغÚÁÏ the seller quickly reached out to me about the issues I had. They quickly offered and arranged a replacement. While I had low expectations I decided to have one more go, expecting to swiftly dispose of the new unit.
I'm glad to say that the new (THIRD) unit works as expected based on my quick tests - although the meter as a whole is quite slow to update and appears to achieve it's measurement accuracy by a lot of averaging and smoothing of readings.
As the seller was quick to reach out to attempt to rectify my issues, and the 3rd unit appears functional; I have decided to upgrade my review from 1 to 3 stars. I still have significant doubts about quality control and longevity and will likely replace with a more expensive meter sooner rather than later.
------------------------------------ Original review: 1 star. Cheap, nasty, poor quality and totally useless for any work
By far the worst multimeter(s) I've ever used. I bought one recently due to the promising spec sheet and good reviews. When received it had no continuity through leads. Due to the good reviews I accepted that sometimes issues happen and ordered a second one.
Second one received, when measuring resistance across the leads (touching metal parts of leads to each other) measured any random value between ~5 ohms and ~50K ohms. Swapped leads from second unit onto the first unit and it was just as bad. Noise in voltage readings similar. At times 20V was shown on the meter just from moving the probes slightly, when not touching any objects. When tested against a known 12V source the accuracy wasn't even close.
Appears that the leads are horrendously bad but even touching the meter during measurement results in the readings significantly fluctuating. Wouldn't trust it even slightly, and that's before we get on to it's supposed 600/1000V rating. Save your money and buy literally any other brand. This meter is no better than taking a wild guess based on no availabile information.