Product details:

Lincoln Electric 3350 PAPR Headgear KP3942-1 Air duct is integrated above the head with baffles to control air flow direction Easily adjustable design for optimal fit and comfort Designed for use with Viking 3350 PAPR. Includes sweatband KP3943-1 Part No. KP3942-1 Can be used in combination with Pipeliner helmets. Some modification is required.