1. This ear cotton is suitable for sound conduit holes with a diameter of 4.5-5 mm 2. Comfortable, soft and fully fit the ear canal 3. Closely fit and isolate noise 4. Simple installation and portable use Product name: Memory foam earmuffs Colour:Black Material:sponge Package Contents: 3 pairs x memory foam earmuffs Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real . The measurement allowed error is +/- 1-3cm.