Quick open up of the NJTY T21D and comments.
Positive: Cheap ($15-20 USD Aliexpress) 6000 count TRMS hand-sized meter, sturdy construction with rubber boot. 3xAAA cell. NCV, Capacitance, Temperature (usual K-Type banana probe included), frequency, magnet attachment, led light, APO, backlight. No trouble lighting blue/white leds. Seems fast in measurements. Marked as Cat-II 600v (I rate this as a positive because it's at least "conservative")
Negative: minimum current range 60mA - there is no uA range. Manual has many errors, it's been copy-paste-badly-edited from a 2000 count obviously. Fuses are 5x20mm 250v (glass as supplied) but there is no warning on the current input jacks about that (there is a warning in the manual however not to use current ranges on more than 250v open-circuit voltage systems). The battery compartment door has fuse ratings moulded into it, but they are wrong (again, from a 2000 count meter obviously). The current shunt is a 0.005 Ohm surface mount resistor, for a 10A current input. Input protection.... it has a tiny PTC. Probes are... not great, even for a cheap meter, well, they're not hopeless, not like on one of those $5 meters, but they are not as good as the probes supplied with the PM8233E, or if memory serves even the RM102, they are rated 1000v and wire marked as such.
Sigh. China. Just a little more effort please. The general construction physical durability and features are great for the price range, but let down by details, needs a 600uA range (or at least 6mA), a proper current shunt capable of 10A continuous, a tiny bit more input protection, somebody to spend an hour correcting the manual, and change the silkscreen for the current ranges to "10A/250v" and "600mA/250v" respectively.
Larger/more photos at the Imgur galleryComparison with ADM02 (MS8233E and others)
About hand-sized
Magnet is removable, note that some sellers may not be sending with the magnet due to customs, this one got through with it still in place.
Bail is a resonable angle, but of course it's not a one-handed operation to change the dial while on the bail.
Rubber boot is easily removed and replaced
Tiny little PTC hanging off the board between the jacks, note the 0.005 Ohm "Shunt" and glass fuses.