This unit is great if you have more than one dog. You can use it for up to 4 dogs. I currently own two dogs and this product works pretty well. I?m amazed by the light function which helps me locate my dogs even in the dark. I also love that this product comes with rechargeable batteries. I?m also loving the color-coded buttons which corresponds to the collars that your dogs are wearing. Makes it easier to control your dogs. I?m knocking off 1 star from the rating because the unit is quite expensive. But other than that, this product performs excellently.