Being a crocheter mainly (and sometimes making an attempt at some knitting) I like to use hooks with handles and have collected a few old bone hooks that aren’t marked with sizes.  This creates a problem; the usual gauges designed for knitting needles don’t allow me to measure my crochet hooks, even the gauges that say they are for crochet hooks can only measure the very simple aluminium types because they expect you to slot the back end / non hook end in to the hole.  I’ve searched for years for a gauge that can measure all my different crochet hooks as well as any knitting needles, should I choose.  There aren’t very many that can do the job! When the one I did find broke and was discontinued and another had some sizes missing I had no choice but to start on the journey of creating my own – which is how Dualgauge was born.