This Sanitizing Bag, with built in charcoal filter and air release valve, is designed exclusively for use with all Sleep8 Cleaners & Sanitizers.<br><br> The blue Sleep8 Sanitizing Filter Bag includes a built in charcoal filter, visible as a gray rectangle near the top, that enables it to safely process activated as it is pumped into the bag; and a round white air release valve that releases filtered air as it is used. The Sleep8 bag may, or may not, inflate during sanitation depending on how quickly air is passed through the filter and air outlet port.