The PetSafe Vibration PLUS Add-A-Dog Collar can be used as a replacement collar or to add another dog to the PetSafe Remote Trainer with Vibration or the Remote Trainer with Vibration PLUS training systems. Features: Safety Time-Out: continuous static correction automatically stops after 12 seconds. Waterproof, rechargeable receiver collar. Good/low battery indicator. Compatible with PetSafe Vibration Remote Trainers: Remote Trainer with Vibration – PDT00-12892 and Remote Trainer with Vibration PLUS – PDT00-12894 For dogs 8 pounds and up or neck sizes up to 22″ Range up to 1/2 mile 15 levels of adjustable vibration correction Choose from quick vibration, continuous vibration, quick static, or continuous static correction.