Silver Mamas nursing cups are handcrafted by fully licensed Silversmiths. They are made of genuine 925 sterling silver and it doesn’t contain Nichel. Silver is naturally anti-microbial, antibacterial, antifungal and anti-inflammatory. 

925 silver is the purest form of silver that can be molded into shape and allows us to have more durable product. 

No, it is not necessary But if you will feel better we suggest to rinse your nipples delicately with warm water.

CDC recommend that infants be exclusively breastfed for about the first 6 months, and then continuing breastfeeding while introducing appropriate complementary foods until your child is 12 months old or older

It is totaly natural with silver products but it doesnt change effectiveness of the them.  You can just wash it with warm water and baking soda to remove tarnishes.

They are available in two sizes, Regular C cup or less, Large C Cup or more.