Hi bullbull,
I know 保嬰單 is good but I haven't give it to my BB before. I remember when my BB wake up at night when he is small, some mammies suggest me to buy 保嬰單. Before I went to buy this, my BB start to have good sleep at night la. I think the drug store person will tell you how to give it to your son. Or, inside it will have instruction sheet tell you how to use.
Bull bull definitly was scared by those rude "animals"!