• Replacement part to use with 3M Ultimate FX Full Facepiece Reusable Respirators FF-401, FF-402, and FF-403 (sold separately) • Designed for use with the 3M Ultimate FX Full Facepiece Reusable Respirators (sold separately) • Protects the lens of the facepiece • Easy to fit over lens • Measures 12.7" overall width x 6.4" overall height