The SportDOG Brand FieldTrainer 425XS is our smallest and lightest e-collar built for in-the-field training or hunting with close working dogs. This 'S' model (SD-425XS) was built for high-drive, more stubborn dogs by offering a higher static stimulation range than the 425X. Consistency and perfect timing are critical to developing your sporting dog, so the remote is quickly and easily operated without having to look at it - which lets you focus on your dog and not your equipment. With only a slight movement of the dial and the push of a button, you will be able to deliver a tone, vibration, or one of the 21 levels of static stimulation. Use these stimulations to communicate with up to 3 dogs (with purchase of Add-A-Dog; collars) out to 500 yards with any of the 425 models. SD-425XS Features: - Upgraded version of the SD-425S to provide 21 levels of static stimulation (instead of 7) and easier functionality - Designed for high-drive, more stubborn dogs - 500 yards of range - 21 levels of static and the option to train with vibration (buzz) and tone (beep) - Designed for ease-of-use and no look operation - More levels of stimulation allow for more customized training - Upgraded, matte collar strap for Receiver - Expandable to 3 dogs with purchase of additional Add-A-Dog collars (SDR-AF) - Waterproof and submersible to 25 feet using DryTek technology - Rechargeable lithium-ion batteries last 50 - 70 hours per charge - 2-hour quick charge with included split plug charger - Fits dogs 8 pounds or larger with neck sizes 5" - 22" (small, medium, large, extra-large, giant) - Remote Transmitter button functions can be customized - Training tool for safety, off leash, recall, control, getting attention, obedience, correcting bad behavior, and ensuring commands are followed.