Item Type:Ear PadsOrigin:Mainland China Memory Cotton : The earphones are made of memory cotton, which means they will fit comfortably in your ears and won't cause any discomfort or irritation. Sound Insulation and Noise Reduction : The earphones provide excellent sound insulation and noise reduction, allowing you to enjoy your music without any distractions from the outside world. Slow Return Earmuffs : The earmuffs are designed to slowly return to their original shape, providing a comfortable fit that won't cause any discomfort or irritation. 4-5mm Inner Hole : The earphones have a 4-5mm inner hole, making them compatible with a wide range of devices including smartphones, tablets, and laptops. Description: Product Name: Memory Sponge Earplugs Using headphones: 4.5 inner diameter in ear headphones Size: 13/0.51mm/in, inner diameter: 4.5mm Features: Comfortable and breathable, noise reduction and sound insulation, not easy to slip off Notice This product is not waterproof and can only achieve moderate sound insulation effect, but cannot achieve complete sound insulation