Audio Control SA3052 Real Time Spectrum Analyzer w/ Battery & Port Internal Battery Pack with Intelligent Charger | Parallel Printer Port for Hard Copy and Documentation Soft Carrying Case with Storage for Mikes and Cables | Never Loses Memories or Programming Optional Accessories: A-C Weighting Filter | Affordable, Accurate, Professional-Grade Real Time Audio Analyzer Self-contained, No computer required | Thirty Bands (25Hz-20kHz) plus Broadband SPL Six Non-Volatile Memories plus Averaging | Discrete Fourth-Order ANSI Class II Filters | Digital SPL Display (0.1dB resolution) | Built-in Digital Pink Noise Generator | Calibrated Microphone Included