WK4300 Justin Men’s Actuator Electrostatic Dissipative Composite Toe 11” Wellington Boot. The WK4300 combines comfort, durability and protection in one hardworking design. Featuring the J-Flex Comfort System, the WK4300 will feel broken in before you even put them on your feet. The WK4300 has Justin’s patented J-Flex Flexible Comfort System—a leather covered cushion ESD insole that returns energy to your foot and a triple density insole board that combines strength and flexibility. Additionally, this full grain leather boot is non-metallic and has Justin’s patented Stampede dual density rubber outsole with slip and oil resistance. Composite Toe. ESD Rated.