Product Description: 1: Firmware upgrade 2: small size 3: Self-strap PWM signal 4: Easy to carry 5: One-button reset button This FNIRSI 138PRO portable oscilloscope is small, and this oscilloscope is only 65 * 60 * 18mm, which is more suitable for carrying it with traditional oscilloscope. If you're looking for new oscilloscopes, try this product, it won't let you down. Features: Portable oscilloscope: This oscilloscope is smaller than the traditional oscilloscope and is more suitable for carrying it. One-button automatic adjustment: One button automatically sets all parameters and fast waveform measurements. Long press the auto button quickly calibrate the baseline. Three trigger modes: Test a single trigger mode of a non-periodic signal, the automatic trigger mode of the test cycle analog signal and normal trigger mode for testing digital logic signals. PWM square wave output: This oscilloscope has a PWM square wave output function with a frequency range of 0-80 kHz, a duty cycle of 0-100%. Application is widely used: This oscilloscope is suitable for automotive maintenance, DIY, home appliance repair, experimental teaching, etc. Parameter Sample rate: 2.5ms / s Bandwidth: 200khz voltage range: X1: 40V (VPP: 80V) X10: 400V (VPP: 800V) (Type3 & 4 only) Trigger mode: single, automatic, normal Coupling mode: AC / DC PWM output: 3.3V Frequency: 0-80khz Duty cycle: 0-100% Packing size: 65 * 60 * 18mm / 2.6 * 2.4 * 0.8in