Martingale collar or Half check collar. Perfect for Whippets, Greyhounds and other sighthounds. Escape proof collar for small headed dogs. – Toodlepips Designs
Leather Martingale Collar - Petiquette Collars
Cobalt Blue Swiss Velvet Martingale Collar | Velvet Collars by Doggy Boho
Martingale Dog Collar Collar - How to measure, fit, and use martingale dog collars for leash walking - YouTube