Your search for sennheiser set 840 returned the following:

Wireless TV listening system with in-ear headphones

IN STOCK

27 people say 

• transmits sound wirelessly from a TV or audio system
• RF wireless transmitter range: up to 100 feet
• selectable hearing settings include optimized speech intelligibility and treble emphasis

Extra headset for SET 840 TV wireless listening system for TV

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2 people say 

• receives sound from a Sennheiser SET 840 TV or SET 840 S wireless TV listening system
• RF wireless transmitter range: up to 100 feet
• built-in volume and balance controls allow individual settings for each headset

Hearing aid-compatible wireless TV listening system

IN STOCK

9 people say 

• transmits sound wirelessly from a TV or audio system to your hearing aid
• RF wireless transmitter range: up to 100 feet
• selectable hearing settings include optimized speech intelligibility and treble emphasis