BK Bruel & Kjaer Type 2203 Precision + 4135 Mic!

A Used Bruel & Kjaer Type 2203 Precision Sound Meter Frequency Analyzer With Bruel & Kjaer type 4135 condenser microphone. I do not know if this unit need calibration or work properly. The light turn on, the meter works and the light inside too. It look like it was well maintained, there is scratches, tape residue and missing the 4 little screws to keep the batteries door closed, the last owner put tape to close it. Very small hairline crack around the meter screw.