"Edgeroll Assembly, Snap On. Manufactured by Scott for use on HGU-22 series flight helmets like the HGU-26/P and HGU-2A/P. Requires rubber contact cement to install on helmet. Unissued in factory packaging. [Medium: P/N 570-1501-1; NSN 8475-01-063-8713] [Large: P/N 570-1502-1; NSN 8475-01-063-8714] [Extra Large: P/N 570-1520; NSN 8475-01-063-8715]