Ultra-lightweight 40g anti-bark collar with a 0.01-second response time, offering a choice of beep and vibration modes. - Model: Anti-bark collar - Weight: Ultra-lightweight 40g - Response Time: 0.01 seconds - Modes: Selectable beep and vibration modes Thank you for viewing. Used for about a month on a Chihuahua. I am selling it because I purchased another one. The Japanese instruction manual has been covered with a book cover to protect it. ⚠️ The strap was too long, so it has been cut. Fits necks up to 23cm.