The little girl I babysit is teething, so her mom lets me keep this Nuk bottle at my house for when she is over. The Nuk bottle is super convenient and spill proof, which is great because Gracie loves to drop it, throw it around, and shake it all over. No matter what liquid is inside, Gracie hasn't spilled a drop yet! The top is solid and the nipple is made of silicone that Grace has to suck out of in order to get the drink out. It doesn't spill out, so she has to use it like a normal bottle in order to get the liquid out. Grace also likes the bottle because she gets to chew on it because the top is made of silicone. The Nuk bottle is easy to clean and use. The lid screws on no problems, and it doesn't hold a smell after using it with milk or juice. The bottles also come in a lot of cool designs for boys and girls, and they are really cute. The bottles are super functional and her mom approves! When I have children of my own I will definitely be investing in some of these Nuk bottles in order to transition my kids from a bottle to a cup.