... okRib: one rib, two ribs and three ribs on the top of shell could be doneLock type of back ... GH060DescriptionSafety helmet with V rib with 6 cooling vents on top of the shellMaterialShell-ABSWeight380gAccessoriesFabric tape, buckle, pinlock, ratchetColourRed, Yellow ... a sturdy and easy use· Working environment -20°C up to max 50°CApplicationsPetroleum, chemical, power ,construction, miningPackaging ...