Marcons A & B™ is a potent combination of 2 powerful anti microbial nasal sprays. They can be alternated one day A and the next B and so on for a powerful effect to improve the health of the sinus cavity. The combination is based on both Dr. Shoemaker of surviving as well as Dietrich Klinghardt, MD, PhD work with sinus health. Marcons A is a probiotic nasal spray and Marcons B is a colloidal silver / EDTA / Eucalyptol Terpene nasal spray combination.