Review on Smart 4-in-1 DC Electricity Usage Monitor: LCD Display, 6.5-100V Voltage, 0-100A Current, Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt by Jason Przystup

They appear to be accurate, bright backlight, display updates maybe every second or so (good), no noticeable heat. I wish the wires from the amp terminals were longer, but splicing the wires doesn't seem to affect their accuracy. I'm sure someone makes an assembled A and B leg counter, but I haven't been able to find one for a reasonable price. I think I've got about fifty dollars to do with this and it saves me the trouble of removing the circuit breaker cover, pulling out my Fluke multimeter and jumping between legs A and B when checking the load or the Use generator in case of emergency. Of course, manually fitting these gauges into a polypropylene box is time consuming, but I have more time than money. Note: Since I'm six feet, I tried breaking the common leg with the SPST on/off switch. This caused the display backlight to start flickering so I used a 2 pole switch to disconnect the two hot/sensitive wires and the switch now properly/fully turns off the gauges when not in use .