From the manufacturer's official website:

Short sleeve cycling jersey is the ideological successor to the legendary ASSOS Uni. ASSOS fine-tuned and improved it. The result is a product that fully suits the ASSOS standard and, in the absence of the SS.13 (separate catalogue), this jersey would be the STAR! The new ASSOS SS.Uno jersey is the perfect all-rounder, featuring a non restrictive, but adhering, pattern design. It is lighter (235 gr) than the outgoing Uni jersey and is well suited for warm climatic conditions. The improvements are: Plasma Textile (ASSOS exclusivity already used on the Etno) Lighter, better stretch and breathability, brighter colors.

For more information, please visit this product's webpage.