Garmin Delta Replacement Handheld Training Device When paired with a Delta dog device (sold separately), the handheld serves as a "virtual leash," controlling up to 3 dogs, regardless of the breed or coat thickness, at 1 time, up to 1/2 mile away Delta is ergonomically-designed to require only 1 hand to operate with 3 front action buttons for continuous and momentary stimulation, tone and/or vibration. With 3 correction configurations Like all Garmin outdoor products, the handheld is designed to be effective, rugged and waterproof (IPX7) and has a long-lasting rechargeable, lithium-ion battery