SportDOG SDR-AB UplandHunter 1875 Add-A-Dog Collar Accessory - Orange - The original Collar Receiver for the UplandHunter 1875 system. Add another dog to your current SportDOG Brand(R) electronic collar system or replace a Collar Receiver with the SDR-AB Add-A-Dog Receiver. Includes a compact beeper with 9 tones to easily locate your dog. Comes with a convenient docking station that charges the collar and beeper in 2 hours.