From Blackstar: 

The FLY 3 is an innovative, cutting edge 3 watt mini amp which combines two channels, tape delay and the Blackstar patented Infinite Shape Feature (ISF) to create the perfect compact and portable guitar amplifier. It's advantageously small and packs a punch with big TONE, even at the lowest volumes.

The ISF allows you to infinitely change the sound of your FLY 3, which gives you endless possibilities on the tone of your amp. The FLY 3 also features tape delay effects, allowing you to make your amp output resonate during play.

The FLY 3 also comes with an MP3 / LINE IN jack built in, allowing you to connect to your MP3 player, mobile phone, laptop, tablet etc. and jam along to your favourite tracks; the Emulated Output jack can also be used with headphones. Capable of being battery powered, you can take the FLY 3 with you wherever you go as a set of portable speakers.

• 3 Watt compact mini guitar amp
• 2 channels - Clean and Overdrive
• Patented ISF (Infinite Shape Feature)
• Digital 'tape' delay effect
• MP3 / Line In for jamming along or listening to music
• Emulated Line Out for 'silent' practice or recording
• 3" speaker producing true Blackstar tones
• Battery or DC powered
• Revolutionary sonic performance