The signal strength is excellent - works from at least a metre away, so if you are trying to find a break or just to locate the cable position this is the one to buy. I had already wasted my money on 2 others that just didn't work

Bon produit mais trop numérique à mon gout dans le sens où la musique sonne ou s'arrête sans variation, c'est assez compliqué d'identifier le bon fil entre plusieurs sans cette variation radio qu'on retrouve sur d'autres testeurs.

No funciona bien. Es imposible detectar donde está la ruptura del cable. El aparato no hace distinción alguna cuando llega a la parte rota. Sigue pitando igual. Un timo.

I used the Noyafa NF-820 to help me locate a discontinuity in my low voltage landscape lighting wiring. Somewhere in the buried 100’ run, the 12/2 cable had been severed. Looking at the cost and chore of replacing 100’ of cable, not to mention digging a trench to place it in, I thought I would try a consumer-level device like the NF-820. Professional level locators cost thousands of dollars, so I was a bit skeptical that a $60 device (with an admittedly poorly translated instruction booklet) would do the job. Yet it did. In less than 10 minutes, I had connected the transmitter to the head-end of the low voltage system, and with the receiver, had identified the location of the break within 6”. Bottom line, the NF-820 has already paid for itself in parts and labor avoidance in a single use.

Read other reviews before buying. I agree it feels cheap, and the instructions are horrible, but after looking at YouTube of how others use it spent 1 hour to figure it out and 5 minutes to find the break in my underground wire. It works perfectly.I have a Worx robot with perimeter wire. You need to disconnect power to the lawnmower, remove both perimeter cables from the base unit, connect the red clamp to one of the perimeter wires and the black clamp to ground. To do that simple stick something metal in the ground and clamp the black clamp to that metal. Then turn on the transmitter and set the it to strength 3… then power on the receiver unit and set it to 2 or 3 not more. I was able to find the break in wire within 5 cm with this thing…. Amazing. Have to give 5 stars despite the poor instructions