The Master Clamp bolt kit is a custom designed nut and bolt set that works with most all frames using integrated seat clamps and many traditional seat clamps as well. The bolt features a unique head design that accommodates both a 5mm and 6mm allen key. This seemingly small feature makes things just a little bit simpler because we all know the feeling of grabbing the wrong size allen key wrench. This also means no matter which seat system you use you'll only need one allen key to adjust the entire seating setup.