The SportDOG Brand SportHunter 825X is our introductory e-collar to the long-range, SportHunter family. This SD-825X model uses the smallest collar of the family while still providing up to 1/2 mile range for up to 3 dogs (with purchase of Add-A-Dog collars). Designed in the field by hunters and dog trainers just like you, the SD-825X allows you to communicate with your dog using tone, vibration, or one of the 21 levels of static stimulation.