Whether the safe lock necklace will collapse when sleeping depends on the hollowness and weight of the necklace. If the hollow degree of the safety lock is high, although the number of grams is small, it will make the necklace relatively empty, so the chance of being squashed when sleeping will be greater. In addition, if the necklace of the safety lock is easy to fall back when sleeping, it is also easy to be crushed by the back or neck. Therefore, it is recommended not to wear a safety lock necklace when sleeping.