The 6000 series is a reusable respirator that offers the user comfort and convenience. Each facepiece is remarkably comfortable, soft, lightweight and easy to adjust. NIOSH approved for negative pressure air purifying and positive pressure dual airline applications. The half facepieces are each available in 3 sizes (small, medium and large). The low- maintenance design helps minimize time required to maintain the product; just clean as directed between uses and help reduce the need for expensive repair programs.