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6mm black on yellow, and 12mm black on yellow: https://www.aliexpress.com/item/1005001839632629.html?spm=a2g0s.9042311.0.0.6ad64c4diC1FFP
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An image of the labels applied to the battery module wiring test jig:
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References:
These 2 videos on the Voltlog youtube channel were helpful in figuring this out. Screenshot above from the 2nd video link.
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