◆ 2018 UPGRADED INTELLIGENT SYSTEM---The bark collar small dog uses the latest vibration sensor technology which means it will only be triggered by your dog's barking while other dog's barking nearby cannot activate it. ◆ EFFECTIVE & HUMANE---Smart dog bark collar is designed to change your dog's behavior of persistent barking effectively. It aims to train your dog being quiet in a short time with harmless and safe way. ◆ 3 MODES & 7 ADJUSTABLE LEVELS---Sound, vibration and shock modes of this anti-bark collar with 1-7 adjustable sensitivity levels can effectively train your dogs. Select the most suitable mode and level freely as your needs. ◆ RECHARGEABLE & RAINPROOF---Fast recharge by USB cable, fully charged in only 1 hour supports up to 10 days of use. Long-lasting battery life and rainproof design of the bark collar for dogs are available for both indoor and outdoor use in different weather. ◆ EASILY FIT FOR ALL DOG SIZES---Bark collar can adjust the length and tightness fit all small/medium/large dogs within 6.6 to 150lbs.The adjustable strap is made from comfortable Nylon which will not harm your dog.