SportDOG FieldTrainer SD-425 Training e-Collar - DryTek Waterproof Receiver - 7 Adjustable Levels of Correction. - 500 Yards Remote Trainer. The SportDOG Training e-Collar should be used for dogs that are 8 pounds and up. Fits neck sizes 5-22 inches. 7 instantly selectable stimulation levels with low/medium ranges. Tone and vibration options. DryTek waterproof and submersible to 25 feet. Range of Up to 500 yards. Rechargeable Li-Ion. 2-hour quick charge. Low battery indicator on both transmitter & receiver. Battery life is estimated at 40 - 80 hours. Expandable up to 3 dogs.