Features: TinyPFA is a phase frequency Analyzers that can accurately measure the frequency and phase difference between signals apply to two input terminals. The input frequency can be any frequency between 1 MHz and 290 MHz. A typical use is to measure the differences between two 10 MHz clocks. TinyPFA can display phase and frequency differences digitally, and display the relationship between measurement results and time in a graphs. Please note that the maximums frequency difference that can be displayed depends on the measurement time , which is approximately 200Hz/s. Therefore, forTau of 1s, the maximums frequency difference is 200Hz. TinyPFA is a portable battery powered device that uses a USB interfaces for charging and designed with a 4-inch display screen, making it very convenient to carry and operate. TinyPFA is not a frequency meter and its internal reference is inaccurate and unstable. It is only used for measuring the Deviation of two signals with similar frequencies. It can be used to compare a signal with a very accurate reference signal. Specifications: Material:Metal Size:Approx.170mm/6.69''x110mm/4.33''x52mm/2.04'' Package Includes: 1Set Phase Frequency Analyzers note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.