The FieldTrainer® 425 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 or field, or for hunting with close-working dogs, the SD-425 allows you to switch instantly between 7 levels of low/medium static stimulation, as well as train with vibration and tone options.