The high power infrared transmitter incorporates multiple light-emitting diodes (LEDs) for an extended coverage range. The MDR-IF540RKs have a transmission range of twenty-four feet (ten feet when at a forty-five degree angle.) They also receive at a ninety degree transmission angle, ensuring that you have uninterrupted listening as you move around the room. The headband is self-adjusting and sports a snug-fitting wide band. The headphones require one AA battery. If you use an optional alkaline battery, you can expect an impressive one hundred hours of use. If you choose to save batteries, simply use the included rechargeable battery and the supplied transmitter/recharger. Using this recharging system, you can expect thirty hours of use.

The headphones are lightweight and comfortable, delivering quality sound. Sony has installed several technical features to the headphones to ensure a quality listening experience. The thirty millimeter drive units deliver deep bass, low distortion and a wide frequency response range (12 - 24,000 Hz). Ferrite magnets give the headphones high energy at a minimal size and weight. The PET diaphragms offer low distortion and resists bending and flexing. The open-air design allows for ambient noise to enter the ear, a safe and observant feature.

With the supplied UniMatch plug, it is easy to connect the transmitter to various sound sources. These plugs accommodate both the phone jack found on high fidelity components or the mini-jack found on video components. A single volume control is found on the right earpiece for simple volume adjustments. Finally, there is a automatic power switch on both the headphones and transmitter to help conserve battery and equipment life. (The unit turns back on when the transmitter detects a signal, while the headphones turn on when they sense their placement on your head.) The headphones weigh 6.3 ounce and are a modern black color.

What's in the Box
Sony MDR-IF540RK headphones, high-powered transmitter/recharger, NiCad rechargeable AA battery, connecting cable, UniMatch plug adaptor, AC power adapter and user's manual.

Product Description
Pump up the volume and groove about your listening room as you enjoy music or TV soundtracks with Sony's MDR-IF540RK Wireless Headphone System. This complete kit that includes a transmitter and headphones offers features like a Lightweight, open-air design, 30 mm drive units for deep bass, Automatic On/Off, and a Vibration Function (with level volume) for an exciting game and movie experience. Also utilize the two audio inputs to accommodate audio and video sources, the rechargeable battery, up to 45 hours of battery life (optional alkaline battery), a transmission range up to 24 feet, and a transmission coverage angle up to 90 degrees. The MDR-IF540RK enables an easy connection to your home audio system, TV, PC or VCR. Hear the difference.