Features: -Technology : Rotexx: patent-pending Rotary Damping System -Weight: 8.8 oz / 250 g -Inner evacuation channels - Bug net: Vents with mesh to keep insects out. -Construction: In-Mold: Industrial process binding the microplastic and polystyrene together to add superior mechanical properties to these materials -Number of Vents: 11 vents -Stabilizing System: Spiderlock® Solo IV: Easy one-handed adjustment -Straps: Steplock adjustment: Easy and secure straps adjustment. -Padding: X-Static® XT2T: quick-drying antimicrobial material -Certifications: CPSC -Circumference of 18 to 20 inches (46 to 51 centimeters)