This 138pro portable oscilloscope with small size, the size of this oscilloscope only 65*60*18mm, compared with traditional oscilloscopes, it is more suitable for carrying around. If you are looking for a new oscilloscope, come and try this product, it will not let you down. One Button Auto Adjust: One button AUTO setting all parameters and quick waveform measurement. Long press AUTO button to quick calibration baseline. 3 Trigger Modes: The singles trigger mode for tests unexpected non-periodic signals, the automatic trigger modes for test period analogs signals and normal trigger is for tests digital logic signals. PWM Square Waves Output: This oscilloscope with the PWM square waves output function, 0-80kHz frequency ranges and 0-100% duty cycle. Wide Applications: This oscilloscope is suitable for car repairing, DIY, home appliance maintenance, experiment teaching, etc. Specifications: Material: PCB Type:(optional) Type1: without P6100, without battery Type2: without P6100, with battery Type3: with P6100, without battery Type4: with P6100, with battery Battery: 1 * lithium battery, 1250mAh (only type2&4 included) Sampling rate: 2.5MS/s bandwidth: 200KHz Voltage ranges: X1: ±40V(Vpp:80V) X10: ±400V(Vpp:800V) (only type3&4) Trigger modes: Single, Automatic, Normal Coupled mode: AC/Direct current PWM output: 3.3V Frequency: 0-80kHz Duty cycle: 0-100% Package size: 65 * 60 * 18mm / 2.6 * 2.4 * 0.8in Package weight: Type1&3: 53g / 1.9ounce Type2&4: 72g / 2.5ounce Packing list: (Optional) Type1&2: 1 * Oscilloscope or Type3&4: 1 * Oscilloscope 1 * P6100