Memory Foam Earbud Tips: Our premium replacement earbud tips are made of memory foam that provides a comfortable and secure in-ear fit. The super-soft memory foam is 30 times softer than the regular memory foam ear tip for long-period use. Silicone Earbud Tips: Knox Gear silicone earbuds are made of soft silicone material, making them durable and comfortable for your ears. The thinner edges of silicone earbuds make the earbuds flexible and isolate the external noise interference. Protection: Knox Gear soft earbuds guard against dust and keeps earwax, debris, and sweat out of your earphone's nozzle, protecting your earphones, keeping the sound path open, and resulting in improved sound quality and external noise cancellation.