About this item A revolution in sound performance, featuring foam that expands at the perfect rate. Enjoy crisp, clear sound and comfort for an all-day immersive experience. Memory foam is a degradable material; each pair should last up to 4 weeks. Designed specifically for earbuds with a speaker diameter of between 3.3 - 4.3mm. Size: 0.47 x 0.47 x 0.39 inches.