All4pet DC-E50 [2016 Version] No Bark Training Electric Shock Control Collar Two Training Modes 7 Levels of Sensitivity Adjustment Tested for safety and health, Guaranteed the highest level bark control collar in this field High-quality Electronic Collar, harmlessly train the dog whenever it barks, to be used for puppy especially under 8 lbs will not be recommended. Easy and convenient to adjust the sensitivity by buttons up or down, purposely decreases the sensitivity compares with old model Small and lunular shape;Simple and cost-effective, With two modes, beep and stastic shock Automatically enter non-working status for 1 minute after 7 times of continuate training