I am very finicky with lab scales, so I was very skeptical when I bought this for my lab. I must say that it is a very good lab balance. It has both internal and manual calibration techniques. I have been using it at least once a week, up to 3 times a week, and it weighs very well. The glass doors are perfectly built compared to other cheaper plastic-frame balances, which may have trouble closing. With this lab scale, the glass doors open and close smoothly, with no rough handling; they just glide through. The handles for the glass doors are screwed tightly into the glass, which makes it more difficult to suffer from wear. I have had lab scales where the door handles are glued and falling off; this one is definitely not like those.Positives for this balance:-Can weigh up to 10mg accurately.-May be used to weigh 5mg of chemical powders. As a general rule, the lower you go from the "minimal value" range stated by the manufacturer, the less accurate it will be. However, I weighed 5mg of powder from MTT, and it has done the job well. If you do not mind variability in the 5mg ranges and you want an approximate rather than exact measurement, then this lab scale should do the job for you.-Can be used to calibrate micropipettes. I have used it effortlessly to calibrate micropipettes in the volume ranges of 1ml, 200ul, and 10ul, and validated the readings with other high-end lab scales, such as Radwag and Mettler Toledo balances from other lab colleagues. I was surprised that they gave almost the same exact readings. If you have access to distilled water (which I assume that if you are in a lab setting, you should), and if you have the calibration key tool, then you can use this balance to calibrate micropipettes.-The lab scale does not feel cheap. The power brick is not a hollow plastic chamber with a connection to the power outlet. It feels like a power cable from higher-end lab instruments. The lab scale does not feel hollow, nor is it light. The manufacturers took care of their balances.Negatives for this balance:The instruction manual is quite bad. I must say that I figured out how to work with the balance by trial and error with calibration techniques. I initially had the "CAL-ERROR" code, and I was genuinely beginning to think that I had a faulty unit. However, I figured out that in order to calibrate manually, you first have to place the 200g pre-set weight into the weighing dish, press the "Cal" button, remove the weight set, close the window, and then wait for the calibration to complete after you see a "CAL-INT" code. It has to be in this order, or else it will get stuck in the "CAL-ERROR" code. This is not stated in the manual, at least not in the one that I received.Important notes:-ALWAYS make sure to leave the lab scale running on its own for at least 1 hour. This is what most people would state as "warming up the lab scale." To do this, you simply plug it into the wall socket, turn the lab scale on, and just let it sit there for at least an hour. At first, the lab scale will display random values on its screen, such as "0.0012g" or such; this is normal. After approximately 30 minutes, the lab scale will begin to calibrate on its own with a display of "CAL-INT" code, which is good, and the values should be at 0.0000g. In theory, you could use it there, but I am very finicky and prefer to wait the full hour. Even Joanlab states this in their manual. If you, however, begin to weight your powders or chemical substances the moment you plug it in, these three things will happen: 1) First, the weight will be inaccurate; 2) the lab scale may start to calibrate WHILE you are weighting which will display a "CAL-ERROR" code and your weighting values will be reset. You will have to start over again. 3) It will be difficult to achieve reading with no fluctuations in values if you begin to weight right away. Tar button may reset your readings to 0 value but rapidly may begin to go to 0.0012g or more or less. It is best to wait to warm up and have this in consideration the day you have to weight.-Make sure to buy an anti-static dust cover, preferably waterproof (you can never be too safe), to protect your lab scale. It has to be anti-static to not interfere with the readings. It would have been great if Joanlab would have provided one for their balance or sold one separately; I would have bought it. However, you can get anti-static dust covers from Amazon. If you are planning to buy a cover, make sure to make the appropriate measurement of size for the cover and lab scale.Overall, Joanlab has made a very good lab scale here that has the potential to rival other lab balances such as the products from Radwag or Mettler Toledo. Very impressive.