I've ben a TV aerial engineer for about 40 years, on and off - and this economical little unit is really useful. It fits in a pocket, and gives a clear multi-led bargraph of TV signal strength, so is ideal for setting aerial direction accurately on the rooftops.
It's also useful for checking signal strengths in house distribution systems, and diagnosing faults.
There are about 15 or so LED's in the bargraph, which gives a superior accuracy to the more usual 5-led designs.
It also displays satellite signal strengths (although not very well on the internal battery, you need to connect a live sat receiver to the Output terminal to provide 15 volts or so to get a fullscale reading.)
I prefer an analogue needle meter for sat dish alignment, as it's more accurate, but this could be used OK if your normal meter failed, or got left behind.
Altogether, the best low-cost meter I've used.
Rod Buck