Garlock Gylon® 3505 sheet gasketing is made in a process that minimizes cold flow problems associated with skived PTFE gasket material. Made of virgin PTFE resin and glass microsphere fillers, for high compressibility. Gylon® 3505 can be used in moderate concentrations of acids and some caustics, hydrocarbons, solvents, water, refrigerants, and cryogenics. Conforms to FDA regulations. Made for use in Oxygen and Ozone.