Check the listing for details. 1977-1978, some 1979 Ford F350 Dual Diaphragm OE Style Booster F250 upgrade. Condition: New. Listed at 260.00 USD. This vacuum booster has an 8" dual diaphragm. It is meant to be a direct replacement for F350 trucks and a direct bolt in upgrade for F250 and some half ton trucks. These boosters are not made with original tooling. They are very high quality built with modern 21st century tooling. They are functionally identical but they have a slightly different appearance than an oem booster. This has no effect on performance. The snout on the back side of the booster does NOT fit within the oem plastic sleeve that goes form booster to firewall opening. You can cut your oem sleeve down slightly for clearance, or remove it. Ford had three major types of boosters form 1968 to 1979. They had one main differences- the rods that connect to the pedal (or in the case of the cantilever trucks, to a lever). This listing is for the 1977 to 1978, and some 1979, version that has a short straight round rod off the back of the booster, and a flat bar that connects to the pedal. OEM part numbers this is intended to replace for reference: D7TZ2005D