those skilled in the art typically the injector is connected sequentially to an adapter spool blowout preventers and the wellhead on its bottom end while on its top end it may be connected to either a gooseneck or other apparatus this other hardware is not shown here but is well known by those skilled in the art of coiled tubing manipulation injector unit 120 consists of traction drive body 121 and multiple drive modules 80 mounted therein lower transverse flange 122 at the bottom end and upper transverse flange 123 at the upper end are welded to traction drive body 121 to permit bolting the injector unit to the other hardware which is required traction drive body 121 consists primarily of a length of steel square structural tubing approximately 16 u00d7 16 inches in cross section and having approximately a u215d inch wall it may be seen in fig8 that injector unit 120 has a repetitive array of multiple drive modules 80 extending from each of its four lateral sides fig9 shows an exploded oblique view of a portion of the injector unit 120 illustrating how traction drive body 121 holds two opposed pairs of drive modules 80 the components shown in fig9 are arrayed in a repetitive pattern up the length of injector unit 120 identical rectangular coaxial lower and upper drive module ports 126 a b and 127 a b respectively with rounded corners are transversely cut with mirror image symmetry about a longitudinal midplane of symmetry of traction drive body 121 to mount each opposed pair of drive modules 80 ports 126 a b and 127 a b are elongated slightly in the direction normal.