The 3M Full Facepiece Button 7989, Respiratory Protection Replacement Part is designed to attach 3M Head Strap Assembly 78093S (sold separately) to the 3M Full Facepiece 7800S Series (sold separately). Color indicates facepiece size; red=small, yellow=med

3M 22394, Roloc Disc 361F, 50 YF-weight, TR, 3 in, Die R300V, 7000045096
3M 22396, Roloc Disc 361F, 36 YF-weight, TR, 1-1/2 in, Die R150S, 7000045091
3M 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738
3M 01328, PSA Cloth Disc 348D, P180 X-weight, 3 in x NH, Die 300V, 7000045068
3M 21341, Nose Cup Assembly 7881S, Silicone, 7000001919, 5 EA/Case 
