Optical fiber cables with a central strength member encircled by a jacket having ducts which are disposed around the strength member and which receive one or more optical fibers with jacket material between the ducts and the outer surface of the jacket. The optical fibers are free to move in the ducts, and preferably, the optical fibers are tight buffered. Portions of the jacket intermediate the ducts connect to the strength member which resists longitudinal movement of the jacket relative to the core. However, the jacket can be separated from the core by manual pulling force after the jacket is axially and radially cut at a pair of diametrically opposite ducts. Preferably, the jacket has outer surface indicia showing the positions of the slots, and the cables can include water blocking materials.