GYLON® Style 3504 is a PTFE Gasket with aluminosilicate microsphere filler. This style gasket is widely used in glass-lined flanges and other light-duty flanges where available torque is limited. GYLON® Style 3504 creates a tighter seal with improved performance over conventional PTFE which reduces product loss and emissions. The unique manufacturing process minimizes cold flow problems typical of skived and expanded PTFE sheets and has excellent bolt torque retention. GYLON® Style 3504 can withstand a wide range of chemicals for extended service life in a wide variety of applications.