The SportDOG Brand® FieldTrainer® 425X takes the most advanced, industry-leading technology that SportDOG Brand® has ever built into its e-collars and packaged it up in the most compact system ever offered. Ideal for training in the yard, field, or for hunting with close-working dogs, the 425X model allows you to switch instantly between stimulation, vibration, and tone. This new 425X Model is an upgraded replacement for the FieldTrainer 425.