Pheromone diffusers aren't made to stop cat fights because they use F3 pheromones, a territory marker. They help reduce stress but do absolutely nothing to make cats bond with each other. That's why thousands of desperate cat parents tried diffusers without results. They weren't made for it.
Another problem is the diffuser itself. Pheromones are sensitive to heat. Diffusers heat the liquid to release them. That destroys up to 60% of molecules before they reach your cats. That's why CatCalm invented the cold-release gel bead technology.
Diffusers also need an outlet to operate. But pheromones should be released where your cats frequently are, near food bowls, in bedrooms, at your cats' favorite spots. CatCalm Family can be placed wherever you need it, not where an outlet happens to be.