※Shipping service. Special Feature = Internal and External Tweeter Research/Modern Noise Considerations Vol. 3/SR Speaker Research/Sound Field Correction Using New BLT Amplifiers/Partitions/Driver Tube Research/Technology Frontier “VHD Technology” /Published Circuit Diagram: ElectroVoice TL505 Enclosure/Mixing Console and Noise//S59.10.1 published. Since the photograph is a sample, the actual item may be broken or have markings etc.