The Marshall MS-4 MICRO STACK Guitar Micro Amp, 1 Watt, Black. You'll be amazed by the might of the Micro Marshall. 

The Marshall MS-4 MICRO STACK features 2 speaker cabs with a head, a full-stack in miniature form standing at only 25cm x 11cm x 6cm. It includes fully functioning Gain, Volume, and Tone controls. The Marshall MS-4 Micro Stack has a headphone output for those who want to rock in private. Powered by a 9V battery.