The AgION Antimicrobial is a combination of silver ions bonded to a ceramic material called zeolite. The antimicrobial is activated by moisture in the air. As humidity increases (and creates an ideal environment for bacterial growth), the AgION attacks the microbe and successfully inhibits it from growing. AgION Antimicrobial is effective against a broad spectrum of bacteria and adds built-in protection to prevent the growth of bacteria, mold and mildew. The germ-fighting power of AgION Antimicrobial will last for the lifetime of your Great Grip. Learn more about: How AgION works with Great Grips AgION Technologies, Inc. Shipping Rates: Shipping is based on weight and is approximately: 1 2-pack $2.25 2 2-Pack $3.00 1 Home Modification Kit $3.00 Money-back Guarantee: If you are not satisfied with your purchase, for any reason, please return it within 30 days for a full refund.