Assos ijtiburu4 insulator jacket its the newly created assos longsleeve insulator jacket the spiritual successor to the elementone ijtiburu4 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 als tips use it in combination with your s