It took me awhile to install the voltmeter because I had to make a wood enclosure so I could install it in a plastic cabinet. I love this little thing because I can now tell what my battery is doing. I installed a solar collector to charge a battery that would pump water from a 500 gallon tank to water my garden. I never knew exactly what my battery was doing even though the controller has three red lights. Low, medium and full charge. Now I know exactly where my battery is doing. After using the pump several minutes the controller showed the battery at two red lights. Was that good or bad? Now as I use the pump the voltmeter goes down from 14.6 to 12 volts while the sun is shinning. When I stop the pump the voltage starts to rise until it reaches 14.6 volts in just a few minutes. So now I know I need two more collectors and another battery. The photos show what I am describing. The third photo shows a reflection of the underside of the collector and our magnificent mountain view.

I live in the extreme N.E.Wyoming backwoods of the Black Hills, I have many different types of equipment -(a 1974 F-250, my daily driver a 1994 GMC K-2500, my 78 yr. young mother's 2005 Tundra) just to name the trucks, this well built Voltmeter will let me know when something is "not up to standard"- here 70+ miles from any city with parts It can easily become a matter of "life or not" . With the many sensors on even my 21 yr. old GMC, any number of malfunctions could cause one of the pcs. of equipment to not charge, or over-charge, I must "excite" the voltage regulator on our plow truck or it will not kick in the 70 amp. alternator (I have to have 2 batteries for that truck to operate the H.D. hydraulic pump to lift the 500 lb. blade for plowing) I can depend on this small, but very accurate voltmeter to let me know when everything is charging within the parameters that each of our very necessary and highly valued items of equipment that make living "Away from the masses of spoiled and nonsupporting folks" (through no fault of their own, some just can't fathom no modern conveniences) even my internet and TV comes from 3 satellite antenna, that has a certain voltage that must be checked at times- We, my mom and myself, love the beauty of the "wild country" How many folks can watch an eagle on the wing, hear the coyotes, watch a Mountain Lion stalking a whitetail" Things like this small meter from DROK and other simple maintenance items allow even my 58 yr. old crippled up (I have extreme, sever, RA) to live "The Good Life"- Thanks to DROK and to Amazon for making such High Quality (technical too, Digital) Items that help "Keep it Simple" and to all who take time to write detailed reviews about what to expect- Have a wonderful Day, I will!!

Wire quality stinks, other than that, great item. Worked as indicated (used tester to verify accuracy) bright and well made housing. Mounted on the lid of a custom cooler radio hooked up to push button sensor. mounting was easy (if in metal would have been difficult) but that because the material was semi soft. Arrived on time and safely wrapped in bubble wrap. Again only reason for not 5 stars was due to wires are flimsy.

Installed it on my mower for a battery voltage monitor. Just what I needed. Fit the existing hole. Worked great for one mowing; about a half hour. Now completely dead. Not worth the effort to return it.
UPDATE: I couldn't really believe it failed on its own. It happened instantly when the key was turned off. After some research, I discovered that the mower generated a 50V negative spike when the key was turned off. Probably the fuel cutoff solenoid. I built a spike filter to put in between the key switch and meter. Hopefully it will keep such things out of the meter's electronics. I upped the rating to 4 stars.

Cumple las expectativas , su medicion es precisa ( lo he comparado con otros instrumentos)