Hard Hat Suspension, Head Protection Suspension Type Ratchet (4-Point), Fits Hat Size One Size Fits Most, For Use With Comfo-Cap(R), Skullgard(R) Medium Size, Compatible Hard Hat/Helmet Brand Name MSA SAFETY, Compatible Hard Hat/Helmet Grainger Part Number 43FD40, 4LN81, 4MD41, 4MD42, 4MD46, 4MD47, 5KAX0, Compatible Hard Hat/Helmet Manufacturer Part Number 475395, 475396, 475397, 475405, 475407, 475408, 482002