Fizik Arione K5 Tri Kium Rail Saddle Triathlon Saddle K:ium is the combination of a particular metal alloy, a specific tubular design and a special finishing process which increases fatigue performance on the rail surface. Wing Flex Technology- Engineered flexibility along the edges where the inner thighs contact the saddle. Additional nose padding and a seamless front cover Silicon printed grippy dots to prevent unwanted movement