Deep See Thermo-Flex neoprene is a 4-way stretch material that stretches 3 times more than conventional neoprene that has a Nylon laminate. Thermo-Flex panels are located throughout the Quantum 7 to provide ultimate comfort and fit. 7mm Titanium skin-in torso. 7mm Thermo-Flex side Torso panels. 7mm Thermo-Flex shoulder, arm, wrist, and ankle panels. 5mm adjustable skin-in neck panel.