SE4 helmet features: MIPS brain protection system, reduces rotational forces to the brain EPP (expanded polypropylene) chin strap for lightweight, durable protection Two sizes to more accurately fit a variety of head sizes and ages of cyclists, improving overall safety Anatomically contoured 3D cheek pads with emergency release system for EMS responders Plastic visor screws and brass inserts for easy impact Stainless steel chinstrap D-rings Comes with TLD drawstring helmet sock 1325 grams/2.9 pounds PATENTED BRAIN PROTECTION SYSTEM MIPS stands for Multi-directional Impact Protection System, a revolutionary technology that allows the helmet to slide relative to the head, adding more protection against the rotational violence to the brain caused by angular impacts.