If your kids accidentally spill some juice, coffee, urine or even food on your mattress, it will not be absorbed by your mattress, thus preventing permanent stains and foul smell over time.Mattress protectors are thin, wont change the feel of the mattress and are waterproof.They do not even absorb any sweat caused by sweating there by prevents mold and mildew.They can be washed by an Eco friendly laundry detergent & machine wash.People who suffer from allergies benefit from this protectors as it limits the sleeper's exposure to the cause of their sensitivity.