Centurion Adjustable Chinstrap 4 Point Harness S30Y for Concept, Linesmen and Spectrum Safety Helmets One S30Y Centurion 4 point adjustable chinstrap for safety helmets. Fits Centurion helmets: S08 Concept, S09 Concept, S08L Concept Linesmen and S20 Spectrum. 4 point harness provides secure fit, adjustable straps allow modification in fit for more comfort. Polyester Webbing Harness, LDPE clips.