Triple flange design equals superior fit: comfort and protection. The Honeywell North RU8800 series half mask was designed specifically to accommodate hard-to-fit users. It includes three unique features that make it adaptable to almost any facial structure. The wraparound profile forms to the user's face while the facepiece pleats guide the mask towards the face and the triple flange: which includes three distinct sealing surfaces: provides sealing security for greater freedom of movement. These features work together to allow for the mask to fit a wide variety of sizes - ranging from extra small to extra larger. The size small RU8800 is a good choice for extra small/petite faces while the medium/large is ideal for people with broad or long faces.