The Itemduct is a block from Thermal Dynamics used to transport items. Items can be pushed into it by machines or pulled into it by a Servo. Items that enter it will attempt to take the shortest path to the nearest valid inventory they can enter.
There are two types of Itemducts: normal and Opaque. Opaque Itemducts are cheaper and do not render items that pass through them; non-Opaque Itemducts render items that pass through them. This can cause more graphical lag, but can also be more aesthetically pleasing or satisfying to watch.
Opaque and transparent Itemducts can be converted into each other.