A breathing protector may include a filter housing having a central axis, a distal end, a proximal end, a first opening and a second opening. The second opening may be located in a proximal end of the filter housing and the first opening may be located distally of the second opening, such that the first opening is located upstream of the second opening. An exchanging filter may be disposed in the filter housing and a valve seat may extend around the first opening. A rail, located circumferentially of the valve seat, may extend axially and distally away from the first opening. The rail may include a distal end and at least one rib. A valve member may be arranged in a transversal plane to the central axis and engage the valve seat in a closed position. A return spring may press the valve member into the open position.
