What do you want to know about them? The 12V injectors go in at an angle from the exaust side and are outside of the valve covers. The 24V go straight down and are under the valve covers. The use diffrent hold downs the 12V have a nut the screws down around the injector to hold it in place and the fuel line threads onto the top of the injector with the bleed off line attaches to the side of the injector with a banjo bolt. The 24V have a metal hold down that is bolted down on top of the injector and the fuel line connects by a tube that runs through the head and is pressed fit against the injector by the fuel line the bleed off goes through a passage in the head to a connector at the back.