SIZE: Medium; Head straps: Small, medium and large have the same size straps. They are adjustable. Face mask itself changes in size from medium to large.
INCLUDES: Face mask only and storage bag, NO cartridges included, they are sold separately here.SPECIFICATIONS: Cartridges: Two required. Approved by the National Institute of Occupational Safety and Health (NIOSH) and endorsed by the Center for Disease Control (CDC).