Compatible with most welding helmet shells, MSA’s new SmoothDome Slotted Cap is a durable, lightweight, polyethylene helmet with Fas-Trac® Suspension. Providing superb comfort, the hardhat accepts a full line of attachable accessories and meets or exceeds applicable requirements for a Type I Helmet (top-impact) as outlined in ANSI Z89.1-2003, Class E (electrical high voltage).MSA,, (800) MSA-2222