The redesigned Phantom is the only wetsuit with an adjustable fit, delivering power and comfort through its proprietary Core Power System. Paired with our unique Bio-Stretch Zone, this suit gives you unparalleled performance. Please see the size chart in the product images. Note: unless you are at the bottom of a size's range, size up! Bio-Stretch Zone: Strategically placed 2mm panels (under arms and lower back) that allow for maximum range of motion Core Power System: Internal support system that improves posture, enhancing hip rotation and lengthening stroke 5mm Aqua Drive core body panel maximizes buoyancy and reduces drag Thermo-Guard technology on chest, shoulders and legs to retain body heat Quick-release ankle transition panels (horseshoe-cut design) for improved transition time Extended length, reverse-pull zipper with leash for easy on/off and quick transitions Aqua-Flex collar seal to keep water out and prevent chaffing and restriction Super stretch, SCS-Coated Yamamoto 39 Neoprene for ultimate comfort 100% UV protection Technologies & Materials: Aqua Drive Core: 5mm Super Stretch Sleeves: 1mm Bio-Stretch Zone: 2mm Core Power System Material: SCS-Coated Yamamoto 39 Neoprene