Waterproof and breathable membrane. This membrane has a micropore that blocks water tears but allows evaporation to escape, thus becoming breathable. Keep it dry, helping to transport moisture and not allowing water to enter.

It is as warm and soft as the pen but, unlike this, repels water and keeps body heat even wet. Likewise, dry much faster than the pen. Increase the winding effect of this, while it perspires perfectly. It is very compressible and surprisingly light.