Static-rappelling Kernmaster line is constructed with a traditional “mantle” sleeve consisting of 48 strands of polyester. The inside, or “kern,” is a braided core of energy absorbing nylon. The core is fully steam-stabilized to enhance the rope’s flexibility and prevent hardening in service; the braid also bends more easily and with less fatiguing of the core when cycled over sheaves or dropped over a parapet.