Martingale collar. The collar is 5cm (2″) wide.
To measure your dog for a martingale collar you have to use a soft tape measure (or a piece of string). Because the collar needs to slip over the head, you also have to measure the widest point of it’s head. Choose the size that fits within this range to make sure that your collar fits.
Martingale collars are also known as humane choke collars. They provide more control without the choking effect. They are originally made for Sighthounds because their necks are larger than their heads and they can often slip out of regular buckle collars. Martingales are often used for Whippets, Greyhounds, Galgos and other Sighthounds.