Bulb Size and Bases. C7 bulbs are smaller than C9 bulbs by 1 inch. C7 bulbs are 2 inches long and C9 bulbs are 3 inches long. C7 bulbs sit in a base known as a candelabra base and can only fit in this specific type of base. C9 bulbs sit in a base known as an intermediate base.
Indoor cable. Indoor fiber optic cable normally includes tight buffer type, distribution cable, breakout cable and armored cable etc. Cable's job is to protect the fibers from the environment encountered in an installation.
Hundreds or thousands of these optical fibers are arranged in bundles in optical cables. The bundles are protected by the cable's outer covering, called a jacket. Optical fibers come in two types: 1  Single-mode fibers. 2  Multi-mode fibers.