Although the higher end Acaia scales come with a calibration weight, this is a good add-on for the Pearl and other scales that require calibration. It might be too heavy to calibrate a jewelry scale I have, so just consider that if you're choosing between the 100g and 500g. From my poking about, it actually seems like a good price for what's available commercially.

This product has a premium build and includes a sturdy carrying case. I bought it to keep my Acaia scale calibrated… as others have said, it doesn’t make sense to buy a premium scale if it doesn’t stay accurate. I deducted one star due to the expensive price.

Nice addition to my expresso equipment, though was surprised I would need to recalibrate the Acaia scale. Periodically check the scale now, which had drifted over the first couple of years by 1 gram for the portafilter (~520g).

Very well made and accurate. Keeps your scales at their most reliable readings.

If you are spending the money on the scale the extra dollars for the weight are worth it. It would be a shame to be using a high end scale that is not calibrated properly. Build quality is high (as expected) and comes with carry case. Buy them at the same time and it will feel more justified :D