Check the listing for details. SU Carburetor sync synchronizing kit H1, H2, H4, H6, HS2, HS4, HS6, HD8, HV4. Condition: New. Listed at 117.00 USD. BritishToolWorks.com is proud to offer this synchronizing kit for all SU double carbureted cars. This kit makes it a snap to synchronize your carbs without removing air cleaners or ducting. Simply remove the damper caps and install the collars, insert and zero the gages and adjust the airflow with the air adjustment screw so that all 3 carbs read the same. Instructions will be provided.This kit is complete with 2 dial indicators, two brass collars with lock screws and three pairs of extensions to reach the bottom of the pistons. This kit fits all SU carbureted cars except for HiF* carbureted cars like the Rolls-Royce Silver Shadow/Wraith IShipping in the US is free. International shipping is $33.00 BritishToolWorks.com provides tools, parts and services for Rolls-Royce, Bentley and other classic British motor cars.