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 where the needle gauge for crochet hooks is really helpful, because you can simply slide the crochet hook you want to use into the 13 measuring slots and measure it.
The needle gauge is suitable for measuring crochet hooks in metric sizes from 2.00 to 10.00 mm.
Plus, the US sizes are marked on the reverse side of this practical, sturdy plastic measurement aid.
So you can get on with your next crochet project straight away!