Well, this PA bottle is made of high-quality materials without BPA, and it is as transparent as glass and safe for the baby. This material is made of polyamide (PA), which is resistant to wear and high temperature. This trademark and scale don't come off easily. Even if it is used every day, the PA bottle is still brand new. Moreover, PP is a common bottle material on the market at present, and its quality depends on which brand you choose. LOVI, owned by the European brand Baihui Mama, is the best quality of PP and PA bottles.