This is a complete kit featuring the 11 3/4" SA Stainless rotor. The stainless rotor weighs in at only a little more than 4 lbs. It is 11 3/4" OD, which gives it a lot more stopping power than the smaller 10 1/2" model. Over a year of testing has proven that this rotor stops so good, in most applications, no right rear or left rear brake is needed. Everything is in this kit that you'll need. Includes radial-mount, hard-anodized caliper, radial-mount bracket, SA Stainless rotor, Wilwood Trick Inboard Rotor Mount, brake pads, and all mounting bolts/hardware. We've sold tons of these to 305, 358/360, and 410 guys with zero complaints.