Hard Hat Suspension, Head Protection Suspension Type Ratchet (6-Point), Fits Hat Size 6-1/2 to 8, For Use With Omega II Mega Ratchet Cap and Full Brim hard hats, Compatible Hard Hat/Helmet Brand Name OMEGA II, Compatible Hard Hat/Helmet Grainger Part Number 3JPH9, 3JPJ4, 41N876, 41N877, 41N878, 41N879, 41N880, 41N883, 41N884, 41N885, 41N886, 53EA16, 53EA17, 53EA18, 53EA19, 53EA20, 53EA21, 53EA22, 53EA23, 53EA24, 53EA34, 53EA35