I've always been curious about my USB ports' charging/output capability and device current draw, but until now I didn't have a way to test/monitor it. This little device is plug and play. Right out of the box, it displays the USB voltage and current flow as soon as it's plugged in.The device itself plugs into a USB "A" plug (large, rectangular), and provides TWO USB "A" ports, so that one or two USB devices can be plugged into it at the same time. Output port 1 supports charging AND data transport, while output port 2 only supports charging. The device shows the total current draw of the device(s) currently attached. A push-botton provides several other measuring/monitoring modes, but thus far I have not used any of them. I've used this device with AC/USB wall chargers, PC USB ports, cellphones, wireless headphones and a number of other USB charging sources/destinations with great success.Note that the device supports the typical 3 amp continuous USB supercharger rate, and can actually handle up to 10 Amps of current, but only for short periods, as its circuitry is not designed for continuous high current operation. Up to 3 amps continuous is just fine, though, and is typically the max most USB devices deliver/consume.I've been quite pleased with other Drok products, and this device is no exception. I'd happily recommend this product to anyone who wants/needs any power provision/consumption info for just about any USB port/device.

簡単に電圧、電流測定できます。表示も見やすく良いです。

Excelente producto y de buena calidad, gracias

Easy to use but the manual describing the various settings is not great. One setting called capacitance is a term often used in electronics and relates to electrical storage. On this device it is actually the amount of energy in mah (milliamp hours) that is sent to your device battery. This is actually quite useful as it shows how much energy the battery is still capable of being charged with. The variety of displays is really good. The unit has a short flexible dongle which makes it less likely to be damaged by bumping. My only real complaint is that most USB ports are oriented the same way and plugging this device into a USB port results in the display facing downward. The short dongle can be twisted to view the readings but it naturally turns upside down when released.

It was delivered on time. It was well packaged. It came with instructions that provided a general idea of what to expect. The features are as described on the Amazon listing (unlike others). It was simple to use. I like the cable attachment. It might be a little finicky, but I can find a way to rotate it to see the display unlike some of the units that plug directly into the USB port and you need to flip the computer over to see the display. Hard to say how accurate it is. At 5.5 volts It's within 1/100th of a volt of another unit I have. The current drops to zero when charging is complete. The power displayed is the product of the voltage and current. I can't really say how accurate the capacity is. I've used this about a dozen times with no problems so far.

DROK makes great products. Things you didn’t know you needed, or EXACTLY what you needed at very affordable prices.With few exceptions, excellent build quality (doesn’t “feel cheap”).ABOUT YHE COMPANY AND THEIR PRODUCT-Their devices frequently have many features, maybe beyond what you needed included but that’s just it; A great Value!AND, if you’re a casual DIYer you could read up on the stuff you didn’t need it to do and Learn something. I’m well-trained and paid for what I do. Yet every job/client I do typically has an added bonus of some pearls of wisdom for me, or others the next time. Knowledge is Power...Pun intended ;)When I’m looking for a meter or other similar device, I ONLY shop the DROK products. The instructions coming with this product are excellent (see below for more on that in general).THIS THING is great to see current flow, check your charge cables, it’s NOT a way to discharge a battery, and doesn’t really work effectively (for the lay-person) to see charging rates. It’s best for voltage, live load, draw.Nite on cables-I have some ISB cables that are wired weird. They will lower but not transfer data. Some do the opposite. Some have product-specific circuits or chips. You might throw away a good cable. Use this to sort things out.Now, let’s address some of the other reviews I’ve read-A-Reviews should be about the product and not the shipping, Amazon itself, etc.B-Every product ordered, from a 737 to a pencil can have a bad one off the assembly line. Don’t review-shame the seller until AFTER you attempt to rectify things with them.C-Several people report that it’s inaccurate, or never reads any different values. This is actually what it should do, in a way, depending on your intended use. Most modern devices (more and more every day) have “Smart” charging. They regulate the charging to preserve the lifetime of the battery itself. It doesn’t pull full power all the time. That smart charging also helps when you are using a spare battery bank on-the-go.Do you have an iPhone? Check this: Settings>Battery>Battery Health and if “Optimized Battery Charging” is ON, that’s an example of Smart charging.Point a webcam that records at this meter. Go to bed. In the morning watch the recording in FastFWD and you’ll likely see some changes to the readout values.D-STOP taking away stars because the instructions are not written by a Harvard English Professor. Most products are made in Asia and the translation to American English is tough. We have words they don’t. Sometimes these read funny or totally crazy. “Insert the plug to flow watermelon to have extended happy value”. Seriously.If you don’t have a clue how to use something and your expectation is to open the box, plug it in, and Voila! Instant answer or problem solved without any understanding of what you’re looking at, you’re over-reaching. Don’t expect a single small sheet of paper to give you an Electronics Theory PhD.Do This- Read the entire listing product description. If THAT reads crazy, SO WILL the instructions. Move on to another seller.ALSO, search YouTube before purchase for HOW to do your project. Many times, this explains what to do with your new gizmo even before it arrives. In a recent case for myself on a client’s project that just would NOT produce their expected results, I searched YouTube. Not only did I find a solution, I discovered a new product I didn’t know existed, and, just as I describe above, watching a guy install the device completely made up for the “stick-figure” instruction sheet. I was ready to go when I got to her house.AND I came in well under-budget and looked like a genius. What I learned will repay me more than the pay on that 1 job.I even bought a 2nd one of those devices for my own home.

Es bueno aunque no intuitivo en su funcionamiento y lectura de mediciones.

Purchased two different Dual USB Power Monitors to test a portable solar panel and some cables that we recently purchased. This unit worked great and made verifying USB charge cable output a snap.PROS• Display is very easy to read indoors.• Unit size makes it very portable.• Unit is capable of displaying several test measurements.CONS• Display is almost impossible to see in bright sunlight. This was a disadvantage during our solar panel tests.• Because the unit is capable of displaying several test measurements, it can be confusing for some users.• Display does not start by displaying voltage and current readings by default (or at least it often did not start that way when plugged in for our tests). Had to press the button on the unit and cycle through readings to get to the voltage and current setting.• Display does not shut off. For some this is a PRO but for others it's a CON since this does take a small amount of the charging current (Did not test any of the device readings against any laboratory test equipment to verify accuracy of the readings. Our main use is a quick test reading that does not require high accuracy. See no reason to doubt the accuracy claims from the manufacturer. It was very easy to determine the voltage drop of some new "heavy duty" USB cables. We simply swapped individual cables between a fixed charger, the Drok and a battery under charge and noted the readings. A very simple test, but we were pleasantly surprised to see how the larger AWG wire used for the USB power leads in the new cables really made if difference in the charging current.The Drok has two USB test ports; OUTPUT I and OUTPUT IIOUTPUT I -- passes both data and charge.OUTPUT II -- is charge only and blocks all data transfer. This allows you to charge your device from any USB socket without risk of data hacking. The data blocking prevents downloading or reading anything stored on your device through the USB port. This is especially important when you are using any USB port that is shared publicly.This is a good low cost device capable of doing a wide range of tests on USB ports. This product was not provided as a sample for this review, so none of these comments are influenced in any way by the seller.