Sperian 776184 Surviavir Opti-Fit Silicone Full Facepiece Respirator, Large Wide viewing area offering distortion free visibility and optical clarity Nose cup prevents fogging Molded in speaking diaphragm provides improved audio transmission for communication Straps are attached to the rim of facepiece reducing pressure points and distortion of the sealing surface when tightened Optimum fit comfort and superior optics