PSB gets up close and personal with your hi-fi. The team at PSB have taken over 40 years of bringing real sound to real people and packed it into the exciting M4U 4 High Definition In-Ear Monitors. You're listening to music more than ever before, but now you can do it on-the-go in comfort and style with PSB's true-to-nature sound quality. The M4U 4 High Definition In-Ear Monitors are the latest addition to PSB's popular M4U Headphone Series with PSB's very own innovative RoomFeel™ Technology that has won praise throughout the world. With scientifically developed RoomFeel technology, you will be amazed that these in-ear M4U 4s allow you to experience the sound of high performance speakers in a perfect listening room wherever you go. The M4U 4 features a two-way Hybrid Dual-Driver System of dynamic and balanced armature drivers for true hi-fi listening. And buy this PSB M4U 4 In-Ear Headphones Now £229.00.