A water-ballasted barrier system incorporates a concave reflective design, wherein outer walls of the barrier segment are configured in a concave manner. In particular, in various illustrated embodiments, a local device such as a Digital Media Adapter, mobile device, cellular telephone, etc. Selection of parameters also provides power to energy ratios for high power, high energy batteries of at least 10. They can be assembled using cold shrinking and heat expanding. The device includes a body having a zigzag-shaped structure, which forms ducts for said gas flows, and the body is designed for the transfer of heat between the first gas flow and the second gas flow.