Fluval AquaClear 50 Zeo-Carb Insert is a specialized chemical filter cartridge that combines activated carbon and ammonia remover in one. It effectively eliminates discoloration, odors, and impurities from the water while simultaneously absorbing toxic ammonia. Designed for AquaClear 50 filters, this 2-in-1 media improves water clarity and purity and helps maintain safe ammonia levels, especially in new or heavily stocked aquariums. (1 insert)