nasal rinse powder sachets that are mixed with water to create isotonic saline solutions with buffered pH. Customers can buy starter packs that include the device, saline sachets, and a compatible water bottle, or purchase refills separately. Capster supports one-off orders as well as subscriptions that regularly deliver nasal rinse mixtures for ongoing use. Its content and guidance focus on evidence-based nasal irrigation as a non-pharmacological method to alleviate congestion and improve nasal function.