The Silca Mattone Ultimate Seat Pack trades stitched canvas for RF-welded TPU composite panels, creating a seamless shell that mounts tighter to the saddle rails and limits the seams where water can creep in. That construction drops the pack to 44 grams, a 50% weight cut from the original Mattone, without giving up the 0. 4L of storage needed for a tube, CO2, and multitool. A BOA Li2 metal dial replaces the standard Mattone's dial and open guide loop, pulling the pack upward against the rails for micro-adjustable compression that keeps it locked in place. What Our Gearhead(R) Experts Are Saying:"I've hit washboard gravel sections that used to set my old seat bag swinging, and this one just sits there, dead still."