DuPont Tyvek 400 TY657S Pullover Hood with Elastic Opening and Serged Seams, White, Universal Size (Pack of 100). The DuPont Tyvek 400 (TY657S) pullover hood extends over shoulders to provide full head protection. One size fits most. Pullover hood design features elastic face opening. Tyvek garments are composed of flash spun high density polyethylene which creates a unique, nonwoven material available only from DuPont. Tyvek provides an ideal balance of protection, durability and comfort of any limited use fabric technology.