Shure SM18B Cardioid Microphone

Please note that the original  foam 'mouse' has disintegrated and is not included.   The mic is being sold in its original case with literature.

Here are the features from Shure's catalog:

FEATURES

• Microphone angled inside foam so cartridge is approximately an eighth inch from supporting surface
• Low-profile design eliminates hollow sound caused by phase cancellation in ordinary tabletop pickup situations
• Available with either brown or white foam and matching colored cable to blend with typical surfaces
• Designed for altar, conference table, or podium pickup
• Cardioid polar pattern and 150 Hz to 10 kHz frequency response for optimum speech pickup
• Supplied with right-angle three-pin professional audio connector (male) for ease of hookup

SPECIFICATIONS

Type: Dynamic
Frequency Response: 150 to 10,000 Hz, at 25", I m (39.4 in.) from sound source, microphone on flat surface

Polar Pattern: Cardioid (unidirectional), at I m (39.4 in.) from horizontal sound source, microphone on flat surface

Impedance: Microphone rating impedance is 150 ohms (160 ohms actual) for connection to microphone inputs rated at 19 to 300 ohms.
Output Level: [at 1,000 Hz, 25", l m (39.4 in.) from sound source, microphone on flat surface]
Open Circuit Voltage . . . . . . . . . . . -75.0 dB (.I8 mV); 0 dB = 1 volt per microbar
Power Level . . . . . . . . . . . . . . . . . . . . . . . . . . -53.0 dB; 0 dB = 1 milliwatt per 10 microbars

Phasing: Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3

Cable: 2.7m (9 ft.) two-conductor shielded, small diameter, attached (SM18B cable is brown; SMlBW cable is white) with right-angle three-pin professional audio connector (male) designed to mate with Cannon XL series, Switchcraft A3 (Q.G.) series, or equivalent connector.