Great for distance cycling and triathlons, ISM's Prologue features a longer length and a narrower hamstring section to allow more forward and rearward body movement. This unique seat also has ISM's split-nose design with a large cutaway to eliminate pressure and increase your pedaling efficiency. And, ISM integrates the sloped front arms to prevent chafing on the inner thighs. Plus they amply pad this sweet seat with foam and gel padding for top comfort. You also get long chromoly rails for plenty of fore/aft adjustment, a spot for hooking the seat on the bike rack during triathlon transitions and this fine seat meets or exceeds the rules of road racing and triathlon too.