Follows 2pcs Yamamoto ® 039 in 0.5mm thick. Titanium ultra stretch outer / lycra Black ultra stretch interior. Ergonomic and preformed cut at the level of the legs and arms. SCS * Balaclava sleeves, cuffs and ankles for a better seal. Adjustable undercut with Velcro®. This combination gives the freediver extreme comfort, unparalleled ease of movement, a free rib cage for optimum pike air intake, and ultra-low buoyancy to balance the trim in mid-water with a minimum of sealing.