Do I have Sata III, Sata II or lower?

Hello , I want buy ssd for my pc ThinkStation 422236U , and I want to know if I have Sata II or Sata III to buy the ssd. I downloaded the app HwInfo and in Drivers it show first "Sata 6 gb/s @ 3gb/s, and down ATAPI" what does that mean? I have Sata III?

Please help