It comes with everything you need. I put one on a GMC 2015 Denali HD. The instructions are a complete joke, but once you figure it out, all and all not bad. With modification I was able to mount the provided button in a 12 volt accessory plug, very clean. The compressor seems good quality but very loud. If you are not very mechanically inclined or aren't good at basic wiring, hire someone to do this for you. Is it loud? Hell yes its loud, you wont be disappointed.
Easy enough to install. Makes driving by groups of people fun. Or blasting that one neighbor that complains our mustang is too loud.