Our smallest and lightest e-collar designed for the waterfowl-hunting environment, where space is a premium and durability is a requirement. Add another dog to your current SportDOG Brand electronic training collar system or replace a Collar Receiver with the SDR-AXC Add-A-Dog Receiver Collar. With rechargeable lithium-ion batteries, this Collar Receiver features a 2 hour quick charge that lasts 50-70 hours per charge. Using DryTek technology, this rugged collar is waterproof and submersible to 25 feet, allowing it to perform in any weather or terrain. This collar can be customized to fit any dog's temperament with tone, vibration, and static stimulation levels.