Its the newly created ASSOS longsleeve insulator jacket, the spiritual successor to the elementOne.iJ.tibuRu.4 is your second layer outer shell garment, engineered to function perfectly within your ALS Assos Layering System. Use it in cooler riding conditions when you want a heavy longsleeve jersey. The tibuRu operates best when used in combination with the next to skin ASSOS interactive body insulator underneath. Use it in combination with your s5 shorts or your T.607. When temperatures do drop, combine your tibuRu with an ASSOS outer shell such as the blitzFeder or climaSchutz vest or jacket. This allows you to extend its versatility and enjoy it for winter riding as well.