SportDOG Replacement Transmitter for SportHunter SD-1800 Dog Training System Replacement transmitter for Petsafe Sportdog SD-1800 radio dog training system 3/4-mile range for large yards, hunting, field work, sheep trials, and more 7 pre-set modes with up to 16 levels of extended stimulation or 16 levels of momentary stimulation Divides multiple-dog training system into two smaller systems; waterproof and submersible to 25 feet Includes 9-volt battery; antenna and charger are sold separately