Our 3rd Party Tested and Safety Checked Dog Whistle with 49cm Lanyard and Cover With adjustable frequency and frequency lock to stop barking and teach recall and tricks Dog whistle to stop barking, teach recall and tricks: Yes, we have developed a better dog whistle to stop barking and help train your dog. More frequency means better results for any dog at any age Adjustable Frequency and Frequency Lock: Yes, our dog whistle has more frequencies. Proprietary precision grinding produces a finer frequency range. Choose a better eco-friendly dog whistle: Yes, we care about quality and the environment. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia