This optional easy to use kit allows connection of Carbmate's 2 x channels (tubes) to 4 carburetor / throttle bodies at once. Synchronize in 3 easy steps : Select tubes 1 and 2 to synchronize the first pair of of carburetors. Select tubes 3 and 4 to synchronize the second pair of carburetors. Finally select tubes 1 and 3 to synchronize the two pairs of carburetors. This kit includes a protective rubber holster that protects against knocks and drops, 2 x rubber hoses and the adaptor.