PetSafe Elite Big Dog Add-A Dog - 535833 For dogs 40 pounds and up. 30-inch collar fits neck sizes up to 29 inches. Range up to 1,000 yards. 15 adjustable levels of static correction plus instant +2 Boost button. Works with Elite Remote Trainers: Elite Little Dog Remote Trainer (PDT00-13623) and Elite Big Dog Remote Trainer (PDT00-13625) Not compatible with Venture Series remote trainers.