Challenge Co., Ltd develops earthquake early warning systems called EQ Guard that can detect seismic vibrations and issue alerts 20 seconds before strong shaking arrives. The system uses sensors that detect initial small vibrations and transmit data to a control center to monitor seismic activity in real-time and send warning signals. EQ Guard has been installed in over 1,000 locations in Japan, Indonesia, Korea, Turkey, Romania, and Papua New Guinea. The system provides a low-cost way to establish regional earthquake warning networks without needing dense seismometer networks.