FXD Safety Boot, Zip Sided, WB-6 FXD WB.6 DURA900™ NITROLITE™ WORK BOOTS ARE LIGHTWEIGHT, FULLY SYNTHETIC, AND PROVIDE SUPERIOR COMFORT AND DURABILITY. THE WB.5 IS A 4.5” MID-CUT WORK BOOT AND FEATURES A DURABLE FULLY SYNTHETIC DURA900™ ADVANCED NYLON BASE UPPER MATERIAL AND OUR PROPRIETARY NITROLITE™ EVA MIDSOLE FOR ALL-DAY COMFORT AND REDUCED FOOT AND LEG FATIGUE. FXD Safety Boot has DURA900™ ADVANCED NYLON UPPER NITROLITE™ MOLDED PHYLON MIDSOLE PORON® HEEL INSERT PREVENTS HEEL STRIKE INJURIES AND REDUCES FOOT AND LEG FATIGUE HIGH REBOUND MOLDED, VENTILATED, ANTI-MICROBIAL POLYURETHANE FOOTBED SRA RATED OIL SLIP HEAT RESISTANT TO 300C KPU TRIPLE THICKNESS BUMP CAP COMPOSIT SAFETY TOE KPU EXO SKELETON MUD GUARD AND EYESTAY SYSTEM YKK™ HEAVY DUTY 10-GUAGE COIL ZIPPER COOLMAX™ ENGINEERED LINING WICKS MOISTURE AND ACCELERATES DRYING SILICONE EMBOSSED ANKLE GUARD PROTECTIVE MOLDED TPU HEEL WITH KICK LEDGES US sizing FXD Safety Boot, Zip Sided, WB-6 Black, Stone or Wheat