For little dogs Fits dogs over 2.3 kg with neck sizes from 15.2 to 40.6 centimetresAdjustable, waterproof With 4 levels of static stimulation and tone only mod for training, receiver collar can be adjusted to dog’s temperamentAdd unlimited pets to your system Keep as many pets as you need safely in your garden with this add-a-dog receiver collar. Compatible with all PetSafe In-Ground Systems except YardMax® and UltraSmart®.Reflective collar strap Adds visibility so you can see your pet better at night