An optical fiber unit for air blown fiber installation, including an optical fiber wire; an inner coating layer formed on an outer periphery of the optical fiber wire with a modulus of elasticity ranging from 0. The rolling pipe is rotatably connected to the slicer and has multiple inlet holes formed trough an external surface of the rolling pipe. 1octane derivatives and their use in the manufacture of pharmaceutical compositions. Accordingly, a stable state in whole is achieved and the rims thereof are overlapped to avoid the electromagnetic interference. The light guide can include light extraction elements, which can be frusta-shaped features for turning light out of the light guide for illuminating the display. Also, the keying portion is only insertable into said keyway to said torque transferring portion when said first and second coupling elements are aligned within a single relative rotational range.