I guess that this fine leaflet dates from 1927, as it shares many of the same graphics as a Cyclo advert dating from that year.
It describes a range composed of two speed and three speed derailleurs. All of these use the trademark Cyclo double cable and helical drive system, but they are different. The two speed has a helical groove in the main rod, and a spigot on the rotating sleeve. The three speed has a spigot mounted on the main rod and a helical cut-out in the rotating sleeve.
Both the two speed and the three speed were available in two variants - the standard 'Le Cyclo' variant has a toothed tension pulley and the 'Le Cyclo Course' variant has a flanged tension pulley wheel.