The Ion Mens Wetsuit Onyx Amp Semidry 5/4 FZ DL represents exceptional performance especially in terms of stretch. Besides, ION’s brand-new and incredibly flexible inside lining Hotstuff 2.0 in combination with the toasty warm Plasma_Plush on the backside ensure an optimal level of heat retention and flex. Featuring our sophisticated Ninja_Knee construction supported by ION’s Maki_Tape, we enlarged the back panel of this suit reducing its weight ever so slightly and increased the area of plushy lining.