Emits piercing ultrasonic tone that dogs hateWorks with most dogsCan also be used to train dogsStop the dog approaching you before it can bite youKeep unfriendly Dogs away.Protect yourself from dangerous dogs while walking， jogging， or bicyclingGREAT FOR: Joggers， Walkers， Delivery people， Mailman，Meter Readers， Sales people， Bicyclists， Police，InspectorsAlso can be used as a torchMaterial:ABSFrequency:35-45HKZ Effective range :Melee RangeColor: BlackSize: Approx. 11 x 5 x 3cm/4.3 x 1.96 x 1.18inchPower: Uses one 9v Carbon or alkaline battery ( Not Included )Package Content: 1 x Dog Repeller