This small 15 cm fits perfectly in the pocket of a Moleskine notebook. (One reviewer mentioned a cork backing, which I don't have.) Of course, I usually use them for journal entries, but you'll be surprised at how many times I've found them useful in my day-to-day life. Life, because it is always with me and at hand.
Accurate Formaldehyde Multifunctional Detector Recording
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π BIAOLING Accurate Formaldehyde Multifunctional Test: Record, Measure, and Inspect with Confidence
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