Battenfeld's M&P Alpha Electronic Earmuff features a folding compact design and amplifies low level sounds. It has an audio input jack that can play your MP3 music, adjustable cushioned ear cups, and includes two (2) AAA batteries.
Specifications:

Type	Electronic
Color	Black/Gray
NRR	23 dB
Quantity	1 Pair
Style	Over the Head
AFT Circuit
Battery	AAA (2)
Compression Circuit
Material	Polymer