Two measurements determine the correct size collar and hoop...
If you need a PRINTABLE TAPE MEASURE, print at 100% scale, and do NOT select the "Fit to page" setting. You can use this to measure your dog, or you can use a ribbon or string, then measure the sting with the printable tape measure.
This measurement helps determine the correct hoop size. Measure from the middle of the neck, along the side of your dog's face, straight to the tip of the nose, using a tape measure or ruler.
Next, check the size of the hoop on the metal yardstick to make sure it’s the right size for dog’s face. There should be 2" (small dogs) to 3" (large dogs) buffer space between the nose and hoop.
*TIP: have someone hold a treat, let the dog lick it while you take the picture. If you are alone, put a smear of peanut butter on your refrigerator, take the picture while the dog is licking.
Wire inside the hoop makes it adjustable up or down, round or oval. If your dog is young or very active, a stronger hoop might be suitable.
Pugs and Bostons, beagles and larger dogs like heelers can all have the same size neck ( for example 15") and each require a diffent bumper and different hoop size. Larger dogs need a wider, sturdier bumper base with the LARGER hoop ( left side) and pugs need a thinner collar and SMALLER hoop (right side).
Beagles and mid-side dogs may need the thinner bumper (right side) with a STANDARD hoop ( not shown). If you are unsure, please contact me with the breed and weight, also I can do a transparent overlay
If you are unsure about the hoop size your dog needs, send me a SIDE VIEW picture of your dog, I will do a transparent overlay with a picture of the collar on YOUR dog for your approval