Castelli took their time before they decided to enter the triathlon clothing market. Clearly the market was certainly ready for some new blood and Castelli's trademark fit and style are a welcome addition.
The basis for Castelli's Tri line is found in Body Paint which was already ideal for triathlon. It is extremely aerodynamic and with functional components integrated into the fabric. One of the key elements is Castelli spent a lot of time in product development eliminating all possible sources of chafing. Castelli has further developed the fabric to make it reflect UV rays and to provide flotation during the swim leg.