The CAF safety cap makes it possible, by preventing gas evaporation as well as any possible fuel spillage, to increase the vehicle’s safety, also in case of full tank overturn. This is achieved by means of the shutter tightproof closing, which protects against any possible fuel spillage by applying heavy pressure onto the tight seal. The CAF caps have been designed to ensure perfect closing and, also, allow easy introduction of the filling pump union, while guaranteeing the air passage and the fuel filling-in (with no fuel spillage). The use of a CAF cap is essential in case robotized nozzles are used. The cap is made of a brass cast, in order to ensure greater strength than the ordinary plastic caps. The flower-like shape provides structural reinforcement that prevent the cap from being broken even in case of heavy shocks.