The 4104 Commentator's Noise Cancelling Ribbon Microphone is of British Broadcasting (BBC) design and used for reproducing high quality commentary speech in noisy surroundings by cancelling out a considerable degree of background noise. 
The 4104 is a proven design and is in use by such broadcasting networks as the BBC, IBA, CBS and ABC. 
The 4104 is not unduly affected by wind noise and can be used in air stream velocities up to 20 mph (32 km) without notable difference in speech quality. With the use of a simple windshield attachment good quality speech reproduction can also be achieved in winds ranging up to 40 mph (64 km) or more. 
The polar response is bi-directional allowing several commentators to make clear individual commentary while working closely side by side.

Microphone Type: Pressure gradient transducer ribbon microphone.
Ribbon: Corrugated aluminium ribbon protected by fine woven nylon
Gauze.
Polar response:  Bi-directional
Impedance:  300-ohm
Frequency response: 60 Hz to 12,000 Hz
Sensitivity: -50db W.R.T. IV/Pa
Distortion: <1% THD at 120db SPL
Connector:   XLR-pin 2 hot
Dimensions: 8"(200 mm) x 2 1/4"(57 mm) x3"(76 mm)
Weight:   10 oz. (283g) 
Finish: Body brown enamel paint with brown pvc covered handle.
Body housing:Brass perforated case with stainless steel nose and mouth
screens, pvc covered handle. Designed to provide a natural holding
position for long periods.
Hum rejection: Equivalent electro-magnetic hum pickup less than 0.0002 dynes/cm2 equivalent acoustic input for 1 milligauss at 50 Hz 
Packaging:Each microphone comes in a foam lined rigid plastic carrying case. 
Options & Accessories:
Replaceable washable plastic hygiene lip screen, packed in 10s. 
Press to talk button.