The balloon, filled with 6000m2 of helium, is attached to the ground with a cable, controlled by an hydroelectric winch. This tourist attraction can board up to 30 passengers (this amounts to around 2500kg (5,500lb)) at 150m (490feet) above Paris. It is 32m (105feet) high, and has a diameter of 22m (72feet).[2]
It has been used as advertising billboard for Fortis, then from 2002 for Eutelsat. In 2008, a partnership was signed with Banque populaire and Airparif. Renamed ballon Air de Paris, the balloon's internal illumination system changes its outer colour in real-time according to the ambient air pollution in Paris, as measured by Airparif. Colors range from green (good), through orange (poor), to red (bad).[3]
This system was completed by an independent lighting (panels light-emitting diode, visible especially at night on the lower part of the shell) stating the air quality near traffic with the same colour code.
On April 18, 2013, a brand new tethered helium balloon was introduced, renamed the "Ballon Generali" (the Italian insurance company Generali has entered partnership agreements to more than 14 years with the Mairie de Paris). Since that day, every year it lifts around visitors. The trip lasts around 10 minutes. In the morning, with optimal weather conditions, the Ballon Generali can reach the altitude of 300m (1,000feet), making it the second highest point in Paris after the Eiffel Tower.