If travelling in or through France it is best practice for a driver to carry a disposable breathalyser. NF-Approved disposable breathalyser.
Unlike other kits where the user has to blow through the tube (which can be difficult for some users, especially the elderly) with the Contralco kit the user blows into the bag without the tube first; the ends of the tube are then squeezed together (nothing to break off, throw away etc) and the air is then squeezed by hand back through the tube.
The kit includes both 1 x tube and 1 x bag per kit and come in a sealed, waterproof plastic sachet.