The collars completely overwhelmed the 10 pound dog and the 20 pound dog couldn't move with it. In addition, the collars are all velcro. The velcro leaves the possibility of the dog breaking free if not attached completely correctly. In addition, if you order a name tag there is no return for the collars even though the name is separate from the collar and attached to a velcro strip on the collar. The company has every angle covered to not stand by their product...do not buy is my recommendation. completely unsatisfactory in all respects. User's recommendation: Do not purchase anything...period from this company.