... weight,Good strength,Good toughness Petroleum, chemical, power ,construction, mining Material: ABS, PE, PP, HDPE is availableColor: red, blue, yellow, white ... rib, two ribs and three ribs on the top of shell could be doneLock type of back hoop: Turning knob (rachet ... ratchetColourRed, Yellow, WhiteSize52-60CMFeatures· Safety helmet with a versatile new shell design of V rib with 6 cooling vents on top ...