ZAP CHECKER products are ultra-sensitive instruments that detect and display Radio Frequency (RF) signals over a broad span of frequencies. They are a new generation of RF measurement tools that employ recently introduced IC technology to measure from very weak to ultra strong signals and differentiate analog from digital communications. They are ideal for wireless installations, detection of covert devices, and detecting and locating undesirable signal sources such as interfering transmissions, RFI, noise and leakage.