The SL145 stem is a perfect example of the determination Zipp engineers display when faced with a challenge. It requires 50 sections of hand-wrapped carbon cloth, titanium bolts sourced from the same Italian producer used by Ducati's MotoGP racing program, and a stainless steel insert within the anodized black faceplate. The SL145 was not easy to design and it's not easy to produce. But the result is the stiffest, strongest all-carbon stem available - as verified by EFBe Laboratory.