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A solid tribute to the unprecedented redefinition of SI base units in 2019. The 7 base units of SI and 7 defining constants chemically etched on a 0.8 mm thick 304 stainless steel card.

The Card of SI

    • The base units of the International System of Units (SI) and their defining constants after the 2019 redefinition are etched on the card
    • On the front side of the card, the 7 base units of SI, which are probably the most important units in the world, are etched with their redefined definitions in 2019.
    • On the back side of the card, the 7 defining constants, which define the 7 base units of the system, are etched with their numerical values, which are exact with no uncertainty
    • All the information and graphics are chemically etched into, or, in other words, "physically" cut away from the stainless steel card. As a result, they are very sharp and clear, and will never fade nor wear off.
    • The card is made of high-quality 304 stainless steel and is tough, strong and corrosion resistant. It is built to last a lifetime or even centuries.
    • The thickness is enhanced to 0.8 mm
    • The luxurious matt surface of the card is resistant to scratches and fingerprints
    • Same size as a credit card (85.5 mm x 54 mm)
    • Made in the United Kingdom
    • All images are for reference only. The photos may be slightly different from the actual item in terms of colour due to the lighting during photo shooting or the monitor's display.
    • The card sleeve shown in the product images is not included. It can be purchased here:
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