http://www.techtails.com.au/2016/04/martingale-dog-collar.html
A no pull collar is a class of pet collar that provides more restricition over the canine without needing the choking effect of a prong dog collar. A greyhound dog collar is also known as greyhound collar. The whippet collar was produced for pets that their necks are larger than their heads, and can easily escape of classic collars. The no-slip collar have acquired popularity between other hound owners.