Grooming brush pet door
 A pet door consisting of an opening filled by the bristles of a brush or brushes. An animal moves through the opening by pushing aside the flexible bristles, which reliably and quietly reseal the opening after the animal passes. Moving through the brushes is as natural to an animal as moving through tall grass or underbrush. The brushes perform a grooming function by removing dirt and debris from the animal's coat as it enters. The brushes have high insulating value due to the volume of air trapped among the bristles. 
E A
E06B A01K
inventional inventional
Thomas E.
Brown