This group includes adapters with 11 mm top diameter (these are often used in Japanese cars). The adapter is fastened to the injector with a clip. These adapters are suitable only for injectors with a 14 mm top O ring.
A short adapter extends (from the top) the injector by approx. 15 mm and a long adapter by approx. 30 mm.
A filter is included in adapter sets with a letter F in their product number. High Flow sets include a bigger filter (high flow type). The material of the adapters is anodised aluminium.