Frequency-Hopping Technology-Creates an infinite number of channels to prevent interference with nearby headphones and wireless devices. Extended Hunting Time-Get up to 30 hours of operation per charge. Recharge the Z-Lynk modules with any micro-USB charging port-on your laptop, in your car, or with a USB power block such as a smartphone charger. Can be used on both VLF (single frequency) and pulse (multi-frequency) detectors. Each module has an Auto-Off function that will switch off power after 30 minutes of inactivity.Garrett Z-Lynk Wireless System includes.