thinksound ms01 in-ear monitor features an acoustically enhanced, 8mm high-definition driver with passive noise isolation. It was voiced by critically acclaimed Audio Engineer and thinksound CEO, Aaron Fournier, and designed in collaboration with Grammy winning musicians and producers. The result is a headphone with advanced studio acoustics and a full range sound that delivers exactly what the pros demanded."Thinksound ms01 monitor series [are] my new favorites …there is no distortion on the ms01s. None. Even at max volume." (William Vitka - The New York Post).The ms01 has ultra-lightweight design and reduced speaker diameter for better ergonomics, and passive noise cancellation to minimize ambient sounds. It also features tangle resistant PVC-Free cables, and a hand crafted, sustainable, wood housing for more accurate sound reproduction. Each pair comes with a cotton carrying pouch, Active Lifestyle Ear Hooks, and four sets of ear fittings to ensure a perfect fit. As with all thinksound products, the ms01 in-ear monitors come with a one (1) year warranty.