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.