Silver Seal Keyboard USB white, antimicrobial and waterproof. The Silver Seal keyboard offers excellent typing comfort while being highly resistant to liquids and contaminants. The antimicrobial effect of Silver Seal products is based on the incorporation of a nano-substance in the plastic. This contains silver ions that destroy the cell nucleus of bacteria and inhibit their growth. The Silver Seal is used in environments where a minimum level of hygiene responsibility is necessary, such as in the food service industry, public service areas (counters, self-service, workstations), hospitals and medical practices, pharmacies, and laboratories.