Check out the Sangean PS-300 Pillow Speaker's Key Features
(Sangean PS300)

• The Pillow Speaker is for Personal Listening
• Listen to Audio Devices with comfort and privacy
• In-Line Volume Control
• Built-in Power Amplifier to Enhance the Audio Output Level
• Switch Off Built-in Amplifier To Power Speaker Directly

Volume

Note

• Install one aaa / um-4 / r3 battery (battery not included) to power the optional internal audio amplifier only connect to headphone jack, as connection to higher output speaker connection will cause damage.
• Requires stereo earphone output. Not compatible with PR-D4 and PR-D7 (mono earphone output).