The covers in Barcelona are usually made of metal , but concrete covers also exist (generally used as information covers) . Their shapes are square , round , or rectangular .
Sometimes, round covers intended for sidewalks are surrounded by a square frame, which greatly facilitates the paving work around them .

Colored covers are usually those that were painted after their manufacture . Gilded covers also exist (generally from a series marking long-established businesses in the city) .

Covers intended for the Municipality of Barcelona sometimes bear the city emblem .
Many covers are intended for the water company Aigües de Barcelona .
In addition, there are covers intended for bodies not connected to the municipality, such as the telephone company Telefónica , the telecommunications company Vodafone , and others.

On a large proportion of the covers, their purpose is indicated, mainly water covers (for example, the text AIGUA POTABLE – drinking water) . Communication covers are identified by the telecommunications provider . On sewer covers, the word CLAVEGUERAM appears, etc.

A series of covers bearing the title “Guapos per Sempre” (“Beautiful Forever”) are in fact plaques marking long-established businesses in Barcelona .

Manufacturers
Many covers were made by Spanish manufacturers Fabregas , Cofunco , Fundiciones Fernández and others.
Covers by the French manufacturer Norinco , the Danish manufacturer AVK , and others can also be found.

Standards
The most common standards are the European standard EN124 and the various load classes (A15 -– F900) .
In addition, the Spanish UNE standard is very common, as is the Spanish AENOR standard , the international SGS , and many other standards.