The Front panel on this unit is engraved "RECORD" along the top with CH1 through CH4 engraved directly under each meter. These meters have balanced, (XLR) inputs and are calibrated to read 0 with a 4dbm, balanced input signal. They can easily be recalibrated using the internal trimpots.
The meters are large (approx 2"x3.75") and brightly lit with 12V incandescent lamps.
All 4 of the meters work fine and all of the stock lamps were replaced with smaller pigtailed bulbs. The case is in Good condition, with 2 long scratches to the top cover, and moderate wear to the rack ears.
Here is some information from B&B Systems
A complete, cost effective metering package from B&B Systems, the MP-4 is four independent VU meters.
This self-powered MP-4 has four rear panel XLR connectors tied to precision, active, buffered, balanced, bridging amplifiers. These amplifiers drive either VU and PPM illuminated meters, all contained in one 3 1/2" package. The MP-4 is available engraved to your specifications.
4 independent input circuits.
Precision buffered, balanced, active bridging amplifiers.
Any combination of VU or PPM styles available, 4 VU, 4 PPM or 2 VU and 2 PPM are standard packages.
VU meters meet ANSI 16.5-1954 specifications for accurate consistency.
PPMs meet BBC specifications.
INPUTS: Four balanced, active inputs with greater than 50k ohms input impedance, four three-pin XLR female connectors.
VU METERS: The VU meters meet all electrical and ballistic specifications established by the Bell Laboratories and ANSI 16.5-1954, as required by broadcast and sound engineers.
PEAK PROGRAM METERS: The PPMs meet all electrical and ballistic specifications established by the BBC. Meters meeting DIN specifications, or other ballistic specifications can be provided on request. Meters are illuminated for easy viewing.
POWER: 115/220 VAC, 50/60 Hz, 50 Watts
PHYSICAL: 3 1/2" High x 19" Wide
14 1/4" Deep, 2 EIA rack units, 14 Lbs. (6.4 Kilo).