Reusable cartridge for the sanitization of water dispensers and water treatment systems compatible with Rapid System connection. The SANIC 250 cartridge is provided, on the lower side, with a threaded cap for inserting the sanitizing product, allowing sanitization and flushing operations to be carried out according to the required instructions. The product is suitable as a technical service cartridge for periodic maintenance operations on compatible water dispensers, reverse osmosis systems and microf