The PNG-2000 is designed as a portable acoustic noise-generating unit that can be used in a variety of ways. The noise generating circuitry has been optimized for voiceband noise masking against listening devices and is designed to reduce the effectiveness of eavesdropping devices such as microphones and tape recorders. When multiple units are used in concert, a complete environment masking system can be easily installed in any environment. The PNG-200 can be mounted to smooth surfaces using suctions cups or simply placed in an area that potential eavesdropping devices may be present PNG-200 Advantages Optimized voiceband noise masking for acoustic interference against listening devices. (Acoustic noise is tailored to voice frequencies). Mounts easily to windows using suction cup (included) to defeat the high tech laser threats. Mounts easily to walls for protection against listening devices that rely on acoustic leakage (ie. contact mics, spike mics, human ear). Portable: Can be carried easily in coat pocket. Multiple units fit easily in a briefcase. Stylish anodized aluminum construction designed for ruggedness and portability Specifications Size: 5.38x3.38x1.25 inches (13.6x8.59x3.18 mm) Weight: 12 oz. (340.2 g) Audio Frequency Range: 300Hz - 3KHz Output Sound Level: MAX 92 dB @ 4 ft. Power: two 9 volt alkaline batteries or AC transformer (120 or 240 VAC) Battery Life: typically 7 hrs. at 1/2 level; 2 hrs. at full level. Includes: Carrying case, AC transformer, and suction cup window/wall mounting kit.