Yong heng 4500 psi compressor for filling hpa tanks... Was working fine back in August then just stopped working I don't know anything about these so it's just sat at home doing nothing, it has the pump with it ,also a spare piston and some gaskets and filters.. I bought a dive tank now so just thought someone with a bit of knowledge might know what is wrong with it and grab a bargain this is collection only as its heavy ......collection is from buckley north wales....