I call this “Big Ring” martingale. I particularly like it because it doesn’t hang up on the bit or reins and slides easily. It has a single adjustment to fit all horses. Bronze hardware.
Big Ring Martingale with Sliding Neckstrap – Al Dunning Collection by Schutz Brothers
Al Dunning has developed AD Tack, a collection of some of the finest quality saddles, bridles, bits, leg protection, show and training equipment available.