Stainless Steel Storage Lids Caps with Silicone Seals for Mason Jars (5 Pack, Wide Mouth) 5 lids and 5 removable silicone seals for Wide Mouth (3" internal diameter) Mason jars per order. They are made of 18/8 304 grade stainless steel and natural colored food grade silicone rubber. Leak proof! Dishwasher safe! Best quality and safest materials available! Plastic and BPA Free - no chemical leach! We love these premium lids for fridge, freezer, and dry goods storage! At any given time you will find dozens of them in use all over our kitchen and home. If you use Mason jars for drinking or storage, it is essential to have an adequate supply of one piece storage lids. Two piece lids work well but they are cumbersome to repeatedly take on and off the jar, they are coated with plastic, and they eventually get rusty. These serve a similar function to the plastic Ball storage lids but are more durable, seal better, and look nicer.