The Standard HDPE frame uses slot adapters compatible with any MSA slotted helmets (included with each frame) and a wide choice of V-Gard visors, Works with or without ear defenders- adaptors stow away when using ear defenders resulting in no more lost parts, Conforms to EN 166 (When worn with appropriate visor) - 3 = Liquids - 8 = Resistance to short circuit electric arc - 9 Non adherence of molten metals and resistance to penetration of hot solids - B = Medium Energy Impact (120 m/s) - T = Impact resistance at extreme of temperatures (-5/+55?C), Conforms to EN 1731 (When worn with appropriate visor) - F =Low Energy Impact (45m/s)