Nony,

They are basically an air cylinder with a split chamber....air in on one side and a low viscosity oil out the other. Like Vampire said, I too thought they were more trouble than they were worth. This may be witnessed by the heavily yellowed label on the package. After doing some test with the first one, I didn't bother removing the second one from the package.

As you can see from the pic, there were two different length cylinders to vary the gear sequence timing. Cylinder OD is 3/4" with the long one being 3 11/16" & the short one is 3 1/8" long.