Is it necessary to buy this kind of bottle to let baby drink water? Baby Is 6 months old~

I will suggest start from straw cup straight away. This type of straw cups with holder to good for motivating the kids to learn how to drink From straw. By the time, you wan them Drink more water, they already drinking well from straw. After can consider Avent, it's anti-leak, it's very good but no holder. No1 try sippy cup fail, end change to straw cup, and master within few days also. No2 straight start straw cups, master on the day itself instead.

Firstly, how old is your baby? For the first 6 months of baby's life, water is not necessary as baby will get all the hydration he or she needs from breastmilk and formula. If baby is old enough to drink water, the bottle you suggested looks good, in my opinion. If baby is older, might I suggest a sippy cup?

it would be more ideal to get baby started on a sippy cup. n then transition to a straw cup and then a normal adult cup. if baby is 6mth old or older and use a nipple cup to drink water, that's going to make transition difficult.

not necessary, my babies started from straw cup