M10 (Metric) threaded zinc plated steel rod.
Metric threads are designated with a capital M plus an indication to their nominal outer diameter and their pitch:
This rod is M10 x 1.5 - which means the outside diameter is 10mm and the threads are 1.5mm apart (the most common thread pitch for M10).
Suits the Munsen ring pipe clips in our store.
225mm long (might be supplied a little longer than this).