Gul Split Toe 5mm Powerboot - Black The Gul Powerboot has been designed using 5mm RS-FLEX MK2 neoprene, making it super warm yet flexible. With reinforced heel and toe the boot has increased durability and strength. This is a great winter boot made from stronger materials to make it more enduring, increasing its lifespan. BLINDSTITCHED: Seam construction. RS-FLEX MK2: 150%  textured super stretch over arms. FX:LITE: inner lining that is super-soft (20% lighter and has 20% less water absorption). LEASHGUARD: prevents the leash catching and velcro adjustable ankle straps for a tight and secure fit.