Barely used over the span of year. Has been kept in its travel case entirely. Tested all functions through the internal hardware checker and everything is perfect. Comes with one of those blue crank accessories, the travel case and of course the USB cable. Take Your Synth Workstation Anywhere!Teenage Engineering's OP-1 synthesizer gives you a complete sampling and synthesis workstation you can take anywhere. If you're going on a transatlantic flight or backpacking down the Inca Trail, then this is the keyboard you want. Loaded with 24 voices, eight synth engines, a flexible sequencer, and a 4-track virtual tape machine, the OP-1 gives you plenty of ways to fuel your creativity. And since it can run for 16 hours on a single charge, you're never tethered to AC when you want to make musicRecord like a pro with the built-in 4-track virtual tape deckDrag-and-drop interface with any Mac or Windows PCStriking user interface with color-coded convenienceMake music anywhere with 16 hours of battery powerCompact synthesizer, sampler, and controller in oneFrom the classic 8-bit Dr Wave sound engine to the String physical modeling engine, the Teenage Engineering OP-1 gives you eight great ways to make cool and creative sounds. You also get two different styles of onboard samplers, including a synth sampler and a drum sampler for adding realistic instrument sounds to the mix. And when you hook the OP-1 up to your computer, you can instantly take control of your favorite virtual instruments, right from its extremely streamlined user interface.Record like a pro with the built-in 4-track virtual tape deckWhen you're ready to record, you'll find the Teenage Engineering OP-1's built-in 4-track "tape deck" to be more than inspiring. Combined with the onboard sequencer, you can create truly funky effects by varying the tape speed (or even reversing it) it real time. And when you add in the OP-1's 4-channel mixer with EQ and Drive controls, you'll be surprised by what you can accomplish.Drag-and-drop interface with any Mac or Windows PCConnect your Teenage Engineering OP-1 mini synthesizer workstation to your computer and it instantly shows up as a mass storage device. This lets you drag and drop audio files between your Mac or Windows PC, allowing you to retrieve recordings from your OP-1, and load new clips up to 12 seconds long into its samplers.Striking user interface with color-coded convenienceYou never have to wonder what you're reaching for, when you grab one of your Teenage Engineering OP-1's color-coded encoders. That's because each color corresponds with the color represented by the graphics displayed on the OP-1's vividly colored OLED display. If you're more creative than technical, you'll find it super easy to tweak settings and shape sounds on this compact keyboard.Make music anywhere with 16 hours of battery powerEven with the volume cranked as high as it can go, the Teenage Engineering OP-1 synth can go up to 16 hours on a single charge. That's a ton of time you don't have to stay tied down to an outlet. At the same time, the OP-1 can go idle for up to 2 years before running out of battery power, so you don't have to keep your OP-1 locked in charging mode when not in use.Teenage Engineering OP-1 Mini Synthesizer System Features:A compact 24-button (not velocity sensitive) synth you can use to make music anywhere, even where there's no AC power8 x synthesizer engines with exchangable architecture let you create tons of unique soundsSynthesizer engines include: Dr Wave raw 8-bit yupe sound engine, FM synthesis engine, Pulse square wave engine, String physical modeling, Digital raw engine, Phase distortion engine, Cluster multiple wave engine, and the ability to expand with future synth enginesBuilt-in 24 Voice Instant Live Sampler lets you sample from the onboard mic, FM radio (optional antenna required), or line-level sourceDBOX drum syn