The covers in San Francisco are usually made of metal

 

or concrete

 

, but there are also covers made of plastic (composite materials)

 

.
The shapes of the covers are circular

 

, rectangular

 

, square

 

, or elliptical

 

.
Covers in the shape of a half-circle or half-ellipse were also found

 

.

No colored covers were found in San Francisco; there are a few gilded covers, usually used for information purposes

 

.
The city emblem does not appear on the covers.

Many covers are intended for the SFPUC - San Francisco Public Utilities Commission

 

and for the gas and electricity company PG&E

 

.
Other covers are intended for telecommunications bodies such as AT&T

 

or Pacific Bell

 

, as well as other users.

The purpose of the cover appears on some of the covers: water

 

, cables and telecommunications

 

, electricity

 

, and others.

Manufacturers
On covers where the manufacturer’s name is indicated, one can find the American companies Christy Concrete

 

and Armorcast

 

.
Many additional manufacturers can also be found, most of them from the United States.

Standards
No standard markings were found on the covers located in the city of San Francisco.