Red Pitaya STEMlab 125-14 4-Input Starter Kit is based on the STEMlab 125-14 board, but instead of two inputs and two output channels, it offers four input channels with improved performance. It comes with Xilinx Zynq 7020 SoC. RF inputs perform better (less crosstalk, noise, and distortion). Switching between internal and external clocks can be done using a jumper or control signal on the extension connector. Users can lock the internal ADC clock to the external reference clock provided through an extension connector upon request.