there were two variants....one was the full-on, plastic fairing from Selle Italia that came up over your arse to smooth airflow in TTs. Popularized in TDF prologues by guys like Thierry Marie. The other was the more conventional San Marco (the one I had) that was like a normal saddle with a ramp at the back. ONCE used them in TTs and Eros Poli used one all the time.....heavy as sh*t!