Comparison : Item # 142-6800, 3M 6800 Medium Full Facepiece Respirator
Item # 142-6900, 3M 6900 Large Full Facepiece Respirator
Item # 760008AS, North 7600 Series Full Facepiece Only - 5 Point Headstrap - Small
Item # 760008A, North 7600 Series Full Facepiece Only - 5 Point Headstrap - Medium/Large