Waterproof collar with belt-style sizing and quick release buckle. One size fits all. Maximum length is 26" (compare to your current dog collar). Trim excess strap after properly fit to the dog's neck. Strap is 1" wide. Note: This strap is included on all collars purchased since November 2025. If ordering a full Roam 350 system, you do not need to purchase this as an upgrade.