if you did some reading, you'd already know the SD headers come with a v band clamp and some crappy horse shoe style clamps.
And that you need to buy two 2.25in band clamps and two 3in band clamps and use the v band clamp with the headers.
ZZP site says they come in 2in, 2.5in and 3in sizes, but you cant click on the 3in size, call them or email them and figure out why, or find another site that sells them, 3in x 6in long.