Blue Seventy Women's Sleeveless Helix Wetsuit (WL) Reverse Zipper: quicker suit exit Knee Flex Panels: textured panels assist w/ flexibility and reduced bunching #39 Yamamoto Neoprene A-Flex inner jersey is laminated to ultra supple 40 cell neoprene to produce an incredibly flexible suit. This A-Flex is also used in: 1mm arms, 1mm arm gussets, 1.5mm TST panels, and 2mm back panel Buoyancy: 5-5-4, including buoyancy in torso for keeping the hips high and promoting an efficient downhill swimming position.