Tychem 4000 Coverall, Bound Seams, Collar, Open Wrists and Anckles, Zipper Front, Storm Flap, White, 3X-Large Effective protection against a range of chemicals Tychem 4000 is chemical barrier film laminated to Tyvek fabric Tychem 4000 is white for high visibility Tychem 4000 provides at least 30 minutes of protection against