This is a nylon neckpiece only.  It has a ring to attach a lead to.  The nylon thickness is 3/16".  It has a bead to slide down to tighten the neckloop.  It will fit an 18" head.  If you need it larger, please specify in the special instructions box.  It will come with a silver ring. 

These come in a slip, kindness, martingale or martingale kindness style. Different prices for each style.