The series of fittings of type LL, L, DL and H come with five tube and ten style versions, as well as a wide range of fittings for different applications. In addition to this, breakage of ferrule will no longer be a problem because of the hardened ridge, while flow resistance is provided by the flared I.D. inside the fitting.
Another aspect worth mentioning is the tube holding mechanism, which gives a stronger feeling and prevents the sliding of the tube while it is being screwed.