Between these sits the £180 RS170 (pictured), a closed-back model complete with switchable 3D Surround processing and Dynamic Bass.
All three models use in-house audiophile-grade drive units, high-power neodymium-iron magnets and adaptive baffle damping for powerful bass, plus the Kleer wireless technology to give a 2.37Mbps peak transmission speed and immunity from interference thanks to automatic channel-selection.
AAA-size nickel metal hydride rechargeable batteries are used, which have the benefit of being replaceable at the end of their working life, and volume and function controls are provided on the headphones.
The RS160 headphones come complete with that portable transmitter, under 10cm in diameter, with a range of 20m and powered by AA batteries giving 24 hours of use. The transmitter can handle up to four pairs of headphones.
Supplied with a mains-powered base-station/charger/transmitter, which has a range of up to 80m the surround-capable RS170 has leatherette ear-cushions and headband, while the RS180 uses a base station giving a range of up to 100m and has velour pads and cushions.
The top-end model also offers automatic level control and a balance control.