16 adjustable levels of vibration and static shock allow you to tailor this collar to your pet’s precise needs. proper fit of the collar is important. do not use this product if your dog is aggressive, or if your dog is prone to aggressive behavior. while the vibration/shock is unpleasant, it is harmless to your pet. you may need to reinforce training with the receiver collar from time to time. the maximum amount of time you can press the vibration/shock …