Until today, the distribution of diffraction gratings was done either by sending pre-paid envelopes for orders done in France, either on a case by case basis for foreign countries. This system, while perfectly operational was however suffering of slowness, mainly due to emails exchanges and mail deliveries delays.
To overcome this issue, it is now possible to directly get your diffraction grating by paying shipment charges by Paypal or bank transfer.
This single payment not only covers shipment for France, but also for foreign countries. Diffraction gratings remain free. You will also receive a user manual. Ordering with the prepaid envelop system is still possible, but you will have to send it to the association headquarter. As a consequence, longer processing delays should occur.
The weak profits, only few cents per order, will be invested in buying new diffraction gratings in order to regularly renew our stock. This self-financed, system, more reactive and flexible, will allow a better distribution of diffraction gratings in France and abroad.