The ST31 Carbon Stem is compatible with Cervelo's renowned Caledonia 5 and features a clean, sleek design for aerodynamic gains. This stem is designed with the same top-tier carbon we've come to be familiar with when it comes to Cervelo, and it offers a super-stiff hold and lightweight construction. It fully integrates with Di2 wiring and the faceplate works with Cervelo's BarFly system for easy mounting. A stiff and light aerodynamic stem for speeding across the tarmac Unidirectional carbon is stiff and durable enough for our rides A contoured shape creates wind-slicing freedom and reduced drag Integrated top cap prevents wind catching for a seamless fit Compatible with: Áspero-5 Caledonia-5 R5 R5-CX.