Who has not experienced this - at some time the marking has been rubbed off the crochet hook and now it is impossible to know what size it is. This is
Hook gauge - Wikipedia
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Swatch Ruler and Needle, Hook Gauge
Made exclusively for Denise by Katy Westcott and her Katrinkles team in Rhode Island, USA. This precision-cut alder gauge helps discern your needle or
Needle & Hook Gauge
Katrinkles - Needle Gauge/Hook Gauge – Sassy Yarns