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.
Optical fiber is used by many telecommunications companies to transmit telephone signals, Internet communication, and cable television signals. Due to much lower attenuation and interference, optical fiber has large advantages over existing copper wire in long-distance and high-demand applications.