Nvm the compressor tube size. It looks like your solenoid has a 1/4 NPT inlet port, and your compressor has an M style connector. You can probably just take the male connector out of the air gun handle and screw it into your solenoid port. As long as it's 1/4 NPT it'll do. If you don't want to disassemble your air gun handle, you can get something like this: https://www.amazon.com/dp/B0000AXCF4/ref=cm_sw_r_apan_glt_fabc_N5P772N4VD7XDADA2Z95?_encoding=UTF8&psc=1

Very similar to what you were looking for, but these have the right thread size.