DT Systems Dog Training Collar with Remote - Micro-iDT PLUS eCollar is a Lightweight Trainer - 900 Yard (1/2 mile) Range - Rechargeable and Completely Waterproof Collars - Bonus FREE Car Charger Expandable to 2-dog or 3-dog system with Add-On collars. 16 intensity levels of Nick and Continuous stimulations adjusted from the Transmitter. Weatherproof Transmitters with No-Slip/Soft-Grip rubber coating. Digital Technology to Maximize Power. Fits small to large dogs