Petco Nubby Blue Shark Dog Toy, 21" L X 5" W NEW QUALCOMM MICROPROCESSOR CONTROLLED BARK DETECTION - a break-through technology and innovative upgrades were implemented in the new version of No Bark collar featuring the newest Intelligent Anti-Injury Chip. The collar has 5 levels of adjustable sensitivity and 3 training modes - beep, vibration, and gentle, safe shock (no shock mode is an option as well), effectively stopping the barking with no harm to the dogs of all types.