Respiratory protection is effective only when it attains proper fit: adverse air that is allowed to leak through the gaps between the mask and the face is extremely detrimental to even the very best of respirators. The 3M 7503 respirator is designed to provide unrestricted protection with prolonged comfort- total dependence on correct fit, regular checking, and proper use. Training is required for the use of the 3M 7503 respirator for contract work, painting, industrial maint