This is the Ibis seat binder for, ahem, weight-weenies. It happens to come as standard equipment on the Mojo SL, Tranny, and Hakkalügi. It will also retrofit to the Mojo Carbon should you want to lighten yours up by 45 grams. This one uses a forged aluminum clamp with a titanium bolt. The Mojo SL/Tranny Seat Binder is available in three colors -- nickel chrome, anodized red, and anodized blue. 16 grams