Why isn't my audio jack microphone not showing in sounds and output on my macbook air...?

hi guys i have recently bought a speedlink spes clip on microphone i plugged it into the 3.5mm jack on the side of my macbook air then i went into system preferences and clicked on sound. then output... but there wasn't anything showing where as if it was showing i would have been able to select my microphone output and not the actually macbook mic. but my new device plugged in isn't showing and i can't use it. i checked the packaging and it says system requirements mac. so I'm good with that because i have one. i am really confused why it isn't showing. i need help please guys. ill be so great full 🙂