Ok it isn't really a meter, but a quick and easy LED indicator for an approximate match.
The maker's spec:
Name: SWR Meter
Material: metal
Using frequency: 3-30MHMz
Maximum power: no more than 100W
Insertion Loss: <0.3dB
VSW: <1.2
Interface: M female
Item size: 25 * 25 * 50mm / 0.98 * 0.98 * 1.97in (not counting M base)
Package size: 80 * 30 * 50mm / 3.15 * 1.18 * 1.97in
Package weight: 85g / 3.00ounce
Maker? Seems to be sold under many brands, maybe mostly same manf as construction details look remarkably similar.
I got it for QRP / mobile / portable operation. So, does it work? Yes, but to be clear, the connectors are SO-239 and despite the label, if less than 10W signal, the lights are not bright but readable. Does it do QRP 5W? Yes, at a pinch, but not bright. Does it give a quick and easy 20W indication of a magloop tune? Yes, with a Xiegu G-90. If the G-90 is angled up for better panel view, the antenna connection doesn't give much room for this indicator. Easily cured with a right-angle connector. Unlike some traditional SWR meters, this one doesn't show FWD power, REF power, ohms, price of fish..., just SWR. Easily found at Amazon, Aliexpress and all the usual suspects.
It feels like a toughly constructed item, suitable for tossing into a go-bag for field use.