Color Changing Mezuzah Case

If you were alive in the 1980's, you'll definitely remember those shirts that changed color when you put your hand on them. And if you weren't alive in the 1980's, here's an explanation: a shirt is something that people used to wear to cover their upper bodies in public. Crazy! In any case, why not put that color changing technology on something that is specifically meant for you to touch?

These mezuzah cases have a thermochromic coating, meaning they change color in reaction to heat. A metal "shin" under the thermochromic layer makes the symbol appear when body heat from the hand is applied. Worry not, even though they change colors, they are still permissible to use on Shabbos¹.

Cases measure approximately 6 x 1.25 inches and can accommodate scrolls up to 4.5 inches tall. Each case comes with heavy duty mounting tape already applied. For indoor use only and ideally should should not be kept in direct sunlight.

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¹ R' Dovid Feinstein - Yad Dodi p.169