CR2550-A Low Cost Remote Current Indicator with Amber LED, 1.5 AAC Turn-On Point

There are no instructions of any kind with this so you need to know how to use it. It looks like you just slip it over the whole cable but it will not work that way. You have to separate the wired and just put it around 1 wire, usually the hot lead. It also comes with something to mount the light to a box, I presume. It's a lens and a couple of other pieces. I never could figure out how to make that work.

I was surprised to see that with only 4 wraps of 14 gauge wire, I was able to light a 12 volt led

Absolutely worked great! It allows me to know if a heat circuit for my water container, in a chicken pen, is actually working! I can see it easily from the house, pen is 100 ft away. Hasn’t missed yet!

Using it to monitor a sump pump. It turns on when the pump is running. Also using one to monitor battery charger shore power switch for my boat. Inexpensive method for being sure essential items are working.

Installed this on the power leads to the heater element on my hot tub. Bright light indicator allows me to see if the spa temperature is at setpoint without opening the spa cover. Easy install.Affordable.

Allows me to monitor the activity of an outdoor pump.

Works as described

great product !,allows me to monitor status of heaters by simply looking at LED.Its not Low Cost, needs to be in $2-$4 range.