Roland Micro Cube GX. This model hold the title of 'most popular battery powered guitar amp of all time'; they've sold very well for a long time now. It's easy to understand why: it's very functional, sounds great and is heaps of fun. There's a bunch of different amp modes, built in effects, inputs for your iPad etc, and it runs on six AA batteries or mains power. Handy! If you're looking for an a spare loungeroom amp or something portable, this is perfect.

Model: Roland Micro Cube GX
Made: China, recent model (serial D8E8238)
Output: 2 watts
Speaker: 1 x 6"
Channels: 1, switchable to several amp modes
Finish: black 
Extras included: power adaptor only

Condition notes: Very clean. No major marks to note, everything is in good shape. Overall: excellent condition.