3M 7283 Easi-Air Exhalation Valve 7800S Series Gas Mask Respirator – Box of 50. Box of 5 bags of 10 units for a total of 50 New in bag valves. Diameter: 1.34 Inch (34 mm) – Approximately. Designed for 3M Full Facepiece Respirator 7800S Series. &#######xA0; Please be sure to include a street address (not a PO Box) for any method other that US Postal Service. &#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B. &#######xA0;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B. Our customers are our highest priority. Media, Books, and Software are non-refundable.