SainSmart DSO211 ARM Nano Mini Storage Pocket Portable Handheld Digital Oscilloscope Portable: The slim and compact design can fit perfectly inside your pocket, without losing any of the integral features found in a full sized oscilloscope! Powerful: System stores files in BMP, DAT, BUF, or CSV format. Uses a built-in flash disk to save/read waveform images. Math waveforms are as follows: DATA, -DATA, Inp+D, Inp-D, -Inp. Output test signal: 10Hz1MHz (1-2-5 sequence step). Can be used in a wide range of environments including academic, electronic maintenance, electronic engineering, etc. LCD Screen: The 2.8inch full-color TFT LCD screen provides a rich display for its smaller size. Rechargeable: A built-in 500mAH rechargeable lithium battery provides power for your oscilloscope use, rechargeable through a mini USB port. Large Storage: Comes with a built-in 8MB storage for saving waveform data and images!