dogIDS Fluorescent BioThane ScruffTag Personalized Dog Collar - Waterproof and Smell Resistant - Comes in Orange, Yellow and Green 1&#34; x 20&#34;: Fits 18-22" neck sizes. To determine collar size, please measure your dog&#8217;s neck with a sewing tape or string. That size will be your dog&#8217;s neck size. The collar sizes directly align with the neck size for the middle adjustment hole on the collar and it can be adjusted up and down 2 inches. See sizing image in product images for more information. HIGH QUALITY: This collar is made in the USA from durable, weather resistant biothane. This collar is also waterproof, smell resistant and made with heavy duty stainless steel hardware. HIGH VISIBILITY: Each vibrant colored collar is highly visible at any time of day. This collar is a great option for hunting dogs that spend time in the field as well as dogs and their owners who enjoy late night walks. BUILT-IN NAMEPLATE: Made with the trademark ScruffTag nameplate, the built-in ID tag holds the most important information right on the scruff of your dog&#8217;s neck. This makes it easy to identify the dog and get it back home. Each nameplate is laser engraved using a high power fiber laser. GUARANTEED FOR LIFE: Each collar is made out of the highest quality materials and has a lifetime guarantee for the quality of the materials as well as the laser engraving.