How to measure

1. For Martingale & 'O'-ring style collar: 

CollarCrfats dog collars with example of a Martingale closure and an O-ring closure
These types of collars should slip over the head of your dog, but not fell off if your dog lowers his head. Please take your measuring tape and measure your dog head at the widest part of it, just before the ears, as shown on the picture below. Please take an EXACT measurement, do it tight enough👇