The Xcel Axis kids back zip 5/4mm winter wetsuit features 100% superstretch Japanese limestone Superprene. It has a plush polypropelene thermo lite internal chest lining for warmth. Glued and blindstitched waterproof seams with internally fusion taped stress points and a watertight back zip. It also adds ankle zips for easier entry/exit. The Axis is our warmest 5/4 Kids Back zip.