• Safety earmuffs with FM radio and built-in antenna. • 3.5mm stereo jack connection (limited to 82 dB) for connecting external radios or phones. • Auto shut-off function after 4 hours of non-use to save energy. Low battery level warning system. • Electronic components protected under the earmuffs to reduce malfunctions. • Memory storage for up to 5 stations. • Product dimensions: 11.9 cm wide, 20.8 cm high, and 14.3 cm long. • Product weight: 0.369 kg.