Selle San Marco Rever with Nanoflex Rail Technology. Nanboflex by Sandvik is exclusive to Selle San Marco. Provides extra comfort without sacrificing weight. Novel design, Aspide style with an innovative addition. Ventilation ports right thru the saddle. The nose has the new taller section for added support. Lorica leather for strength, long wear. CFRP) carbon fiber reinforced nylon/plastic shell. Weight 210 gms.