Holes for knitting needle sizes from 000000 to 35 are also clearly marked with metric sizes. Crochet hooks sizes B through P are etched above the hole where applicable to ensure it is universal for every type of craft. A cut out for measuring a 4” gauge swatch has a ruler that is marked with both centimeters and inches.
We have yet to find another gauge that has this much information in one place! This tool would make a great gift for a beginning knitter or crocheter but is also extremely useful for a lifelong crafter.
(Please note that crochet hooks with ergonomic handles are often made with larger hook heads than the metric measurement of the shaft and will not work with this gauge: i.e. Clover Soft Touch)