The cheapest option to comply with French Breathalyser Law is to buy a disposable breathalyser. These are small and can fit in a car glovebox or under the seat of most motorcycles.
They are single use only and it is advised by the French police to buy two so that you have a spare after using one. This way you will satisfy the law if you are stopped by the police.
Here is our selection of the best currently available on Amazon.