Size and Dimensions:.. X-Small:..Outer Diameter (8mm)...Height (8mm).. Small :..Outer Diameter (10mm)...Height (9mm).. Medium:..Outer Diameter (12mm)...Height (9mm).. Large:..Outer Diameter (14mm)...Height (9mm).. Product Description:.. -Noise Reduction / Isolation Eartips -Specialized Center Line Guard Stopper prevents the diaphragm of the earphones from falling within the ear canal and keeps your eartips centered for maximum sound quality and comfort. -This set contains multiple sizes so you can find your perfect size for comfortable hours of listening. -Studies show you can use the various sizes based on your activity and the amount of hold and isolation you would like. For example while resting a great hold is not needed like as in gym activities. -These eartips isolate sound, provide secure fit, and maximize comfort of your in ear device. -Specialized material conforms easily to the shape of your ear canal which makes for a comfortable fit that reduces ear fatigue and stays in place during activities. -Water-washable, antistatic, removable and replaceable. -Spare, Ideal replacement for any damaged, scratched, defective or lost eartips. -You can also use them, to provide better hygiene - when you change often.... Instructions to Install Ear tips:.. With one hand hold the ear tip and the other, the In-Ear Earphone Driver. Place the Driver of the Earphone in the edge of the ear tip canal. Apply pressure and with a circular motion, twist with one hand clockwise and with the other the opposite direction, until the ear tip has fully covered the Driver of the Earphone. Once you have put them on properly, they will stay on securely