Starting working as soon as I put it on my gelding. No more sucking wind or cribbing. Size guide is a little confusing. I ordered a medium for my 15.1 hand Quarterhorse. It fits perfect.
Weaver Miracle Collar is the BEST. Don't waste money on knock offs. Works great for our suckers.
Fits perfect provided you take the time to readjust for a few day as the leather stretches.