GenFast™ #15 Washer Head (WH) Fastener may be used with GenFlex Polymer Batten Strip or GenFlex (WH) Seam Plate in GenFlex EPDM and TPO mechanically attached systems. GenFast #15 WH Fastener is available in various lengths from 1¼″ to 12″ (31.8 mm to 355.6 mm). GenFast #15 WH Fasteners are manufactured to conform to the physical property requirements of Factory Mutual Specification #4470. GenFast #15 WH Fastener may be used in any GenFlex system for attachment of roofing membrane to approved steel, structural concrete, and wood decks. The fasteners are packaged in white square buckets.