Rongon Handheld 10X Magnifier Loupe LED Optical Glass Magnifying Glass with Light Scale Magnifying Jeweller Jewellery Loupes with Measure Scale

The only instructions that came with this magnifier were on the card in the attached picture. Although the product description on Amazon only says it requires 2 AA batteries, the card indicates that you should only use "Carbon" batteries. By "Carbon", I believe they are referring to the carbon zinc batteries marketed as "Heavy Duty" batteries even though they are only capable of putting out a fraction of the current alkaline, NiMH and lithium metal batteries can. Intrigued and annoyed by this limitation, and also being an electrical engineer, I disassembled the magnifier and analyzed the circuit. If you use alkaline batteries, it will work for a while but it will put many times the rated current through the LEDs and they will probably fail well short of their normal lifetimes; perhaps just after the return period for the product has expired. The housing around the magnifier is black and opaque so, without a working light, this thing is almost useless. Fresh heavy duty carbon zinc batteries may also exceed the rated current of the LEDs but I didn't test that because I only buy alkaline, or better, batteries. For these reasons, I do not recommend this magnifier. If you're willing to take a chance and use carbon zinc batteries or modify the light as I did, the magnifier is actually well built. The lenses are glass so they are scratch resistant and their optical quality is very good for the price. The lenses do not have anti-reflective coatings and the focus is not perfectly uniform across the field of view but they surpassed my expectations for the price and the magnifier is great for casual use. The measuring scales are a little hard to use because they are far from the center of your field of view so you have to look from an angle to see them well. There's a black foot, press fit onto the end of the battery tube, that can be used to hold the magnifier parallel to a flat surface. However, when it's in the position needed to do that, it will not fit in the supplied case. You can work it loose and turn it as needed but this seems like a poor design.For those who know about electronics, the light is implemented as three, 3mm, LEDs in parallel driven directly by a 5 volt boost regulator that is connected to the batteries. Unfortunately, the forward voltage of the LEDs is only three volts and LED manufacturers don't recommend putting LEDs in parallel without additional resistors because doing so often results in uneven brightness and current sharing issues. The only reason this arrangement doesn't immediately burn out the LEDs is because the regulator has a current limit of several hundred milliamps. Thus, the LEDs, which probably have a combined current rating of less than 100 mA, will probably burn out rapidly as forewarned in the instructions when the magnifier is powered by alkaline, or even rechargeable, batteries which are capable of supplying enough power to destroy the LEDs. Had the manufacturer of the magnifier simply put a 110 Ohm resistor in series with each LED everything would be great. I made this change to mine and, although it's not as bright as it used to be, it's still bright enough for examining things indoors and runs fine on alkaline and NiMH batteries. When not using the light for a long time, consider taking out the batteries because the button goes to a pushbutton controller IC that toggles the light on and off with each press by disconnecting the cathodes of the LEDs from the negative battery connection. It does not turn off the boost regulator which draws about 50uA when the light is off. This will kill the batteries in a few years and could eventually cause them to leak.

I bought this to replace another lighted magnifier that broke when it was dropped. This magnifier is well made and work exactly as advertised. The case makes a nice addition for keeping it secure when not in use. I am using this for examining coins and electronics and it works excellent for these purposes. I highly recommend this model for anyone looking for a lighted magnifier for similar uses.

For $15 this is a great tool to have on the shop floor. The leds are bright enough. The magnification is fine for standard inspection of samples during production. For the price, I would recommend having a couple around for operators to use.

I work on grand format industrial printers, use this daily to see my alignment images.Easy to hold, clear, batteries last a while.Great purchase

Love it easy to use and does what it is supposed to.