Able Spacer Mask Medium Child Features: -Suitable for infants -Anti-bacterial -Anti-static properties -Coaching whistle mask -BPA Free The new ABLE Spacer with Medium Child Mask is embedded with silver ion to protect against 99% of all harmful bacteria (demonstrated by ISO 22196 tests). Common plastic spacers can contain up to 40% bacterial contamination that causes harm to the lungs and even pneumonia. How it works: When bacteria comes into contact with a silver ion protected surface, the silver ions inhibit the bacteria's ability to multiply, therefore they die. For use with puffer medication.