The 3M H-700 Series Hard Hat helps deliver lightweight protection and durability for extended comfort. With the new Uvicator sensor. workers have an easy way to monitor their hard hat exposure to the sun. so they will know when it's time for a replacement. These hard hats feature a low-profile design for stability and balance. and include accessory slots for 3M's cap-mounted earmuffs. headgear. faceshields and welding helmets. The H-700 series with Uvicator sensor is available in both vented and non-vented versions. ratchet suspension only.