material and therefore the driveshaft 118 inserts slidably into its central opening the spacer 250 has the same radially expanding characteristics as the end fittings when placed in a state of compression as described briefly above and in more detail below thus the spacer 250 initially forms a moderately good seal where it abuts the driveshaft but it expands radially inwardly and outwardly when placed in compression thereby seating the sidewalls 254 tightly against the outer surface of the driveshaft 118 which creates a substantially water and food particle proof seal at the juncture of the abutting surfaces the spacer 250 has a pair of opposing radially outwardly facing shoulders 256 and 258 that are preferably circular cylindrical and substantially the same diameter as the inwardly facing surfaces of the central tubes 112 a and 112 b a gasket 252 extends radially outwardly from the juncture of the shoulders 256 and 258 and is preferably substantially equidistant from the opposing ends of the spacer 250 the spacer 250 can be any size as will be understood by a person having ordinary skill from the description herein to meet the requirements of the cooperating components in one contemplated embodiment the spacer 250 is about 1 78 inches long the gasket 252 is about 0 25 inches thick and about 4 50 inches in diameter the diameter of the shoulders 256 and 258 is about 3 36 inches and the central opening in the spacer 250 is about 2 02 inches square when the spacer 250 is mounted on the driveshaft 118 it is displaced along the length of the driveshaft 118 until one end seats against the end fitting 230 as shown in fig2 this can be accomplished by.