Hi,
DI's (for 4 cylinder cars) come in two main flavours, Red (for 9000's, GM900's and early 9-3's - for Trionic T5) and Black (for later 9-3 and 9-5's - for Trionic T7)
The Red DI came originally as a unit with a 2ft lead permanantly fixed. From about 1992 thuis was changed so the the Lead was attached to the car and a 8 way plug to connect to the DI.
The earlier version is no longer available and most cars have been upgraded to the later 2 part (lead and di) units.
Be warned though, some of the early type (1 part captive lead) are still being bartered around 2nd hand on places like Ebay. Unlikely but remotely possible.
Andrew