THINKPRICE 2 Pack Dog Whistle to Stop Barking - Barking Control Adjustable Frequency Ultrasonic Sound Training Tool- Adjustable Pitch-Free Premium Lanyard Strap &EBOOK Training Guide Easy To Use And Train Your Dog:Adjustable frequencies,Easily teach your dog unlimited commands such as sit, come, stop barking, stay, and more. Safe Dog Whistle:Will NOT hurt your dogs ears.Use Silent Bark Control for dogs stopping useless barking. Anti Loss:New Dual Anti Loss Features with Special Lock Nut & Cover with Lanyard. Quality Made:Designed reasonable small size & comes in premium metal black color,Long lasting and rust proof.