From the reference box #35
Disque de controle de stationnement - a French parking control probably from the early 50's for 'Zone Bleue', which according to the very detailed map included part of the Champs-Élysée.
It has 'Matin' (Morning) 'Heure d'arrivee' (arrival time) and 'stationnement autorisé' (parking authorised till) times on one side of the dial and 'Apres -Midi' (afternoon) times on the reverse.
All the 'Heure d'arrivee' are in blue type and some have either a blue or red dot screen behind them, I'm not sure what that is indicating, but it looks good. The 'stationnement autorisé' are all in bold, red type that's much bigger than the arrival times.
I'm not sure if it's sponsored by Citroën, whether they produced them or whether they are just advertising on it, but I really like the old logo and graphic on there.
I love this little piece of ephemera, it's a great addition to the reference box and to my moving dial/wheel collection - #35 - Disque de controle de stationnement
Checkout the rest of the reference box items here.