The WRU contains a system for seismic acquisition and radio relay encased in a waterproof aluminum case. The WRU runs from either one or two rechargeable lithium-ion batteries. Dimensions: 14.7Wx 7.2Hx 22.9L cm (5.79Wx 2.83Hx 9.01 Lin.) Weight: 1.86 kg (4.10 lbs.)