The 3M™ Secure Click™ Quantitative Fit Test Adapter Kit is used to conduct quantitative fit testing for 3M™ Secure Click™ HF-800SD-Series Half Facepiece Respirators. This adapter helps measure the respirator's fit to your face to ensure a proper seal. When you need a test done, equip the 3M™ Secure Click™ Quantitative Fit Test Adapter Kit.