1, poor antibacterial grade: 3A underwear can still reach the antibacterial rate standard after washing for 50 times. 5A underwear needs to pass 100 washing tests to keep up with the antibacterial rate standard.

2, material differences: 3A underwear contains more chemical fiber ingredients, hard texture, not skin-friendly. 5A underwear is made of pure cotton, which is soft and breathable and more comfortable to wear.