The Sennheiser IE 4 (article 500432) is an affordable in-ear headphone designed specifically for wireless in-ear monitoring systems and personal monitoring. Musicians, presenters and technicians use it with bodypack receivers such as Sennheiser's evolution wireless IEM range to hear their own mix on stage or in rehearsal without floor wedges. A robust dynamic transducer handles high sound pressure levels and delivers a full-range sound with solid bass and smooth mids, while the universal-fit silicone ear sleeves (three sizes supplied) provide passive isolation from loud stage surroundings. The earpieces are light and low-profile so they sit unobtrusively in the ear, and the rugged 1.4 m cable ends in an angled 3.5 mm stereo jack that plugs straight into a bodypack receiver or any standard headphone output. Nominal impedance is 16 ohms and the headphones weigh around 50 g. They are a sensible spare or entry-level set for bands, churches and rental companies running IEM systems, and are covered by Sennheiser's two-year warranty.