The vibration strength was strong enough for my puppy to get the message but not hurt him. The battery life went for awhile so it could still be effective for awhile. The adjustable collar and lock feature kept sturdy as much as he tried to mess with it he could not.The color blended in and the vibration kept his attention as warning before the shock.It is very effective. Now my puppy is getting over these behavioral hurdles we have been trying to overcome.