You are right. 3 prong plugs are for non turbos. Turbo plugs are single prong, double platinum. And yes, "exl." means excluding. Note. The hose clamps on the turbo ducting usually break when you try to loosen them. Either buy all new clamps when you exchange the plugs, or try this procedure. Loosen the screw on the hose clamp untill you feel resistance. Then, using a pair of channel-lock pliers, squeeze the clamp by placeing the pliers against the screw and the back side of the clamp, which pushes the screw back in to the clamp. There will be a pop sound, then the clamp can be loosened and re-used. These clamps are designed for 1 time use but if removed carefully can be re-used.