Toa PM660U Desktop Dynamic Paging Microphone Balanced Unterminatedtoa s pm-660u is an elegantly styled, compact desk microphone for use in public address, paging & radio communication systemsideal applications include restaurants, offices, warehouses, transportation terminals, dispatch centers & entertainment facilitiesits smooth, natural response provides high quality voice reproduction & excellent articulation to enhance the overall performance of your systemcompact & lightweight, the pm-660u requires a minimum of desk or counter space & is easy to handleto significantly reduce background noise & feedback, the pm-660u features a cardioid pick-up pattern that is uniform over the entire frequency rangethe dynamic microphone element has a 600 ohm balanced output & the microphone is supplied with an attached 8.2 , four-conductor cable with stripped wire endstwo conductors are shielded & are dedicated for the microphone signalthe other two unshielded conductors connect to an auxiliary, normally-open switch contact, used to activate external muting, priority or relay control circuitsthe auxiliary switch contact is closed by using the push-to-talk bar, which also turns on the microphone by opening a second set of contacts that normally short the mic elementa locking lever is provided to keep the push-to-talk bar in the 8220 on position when the microphone must be kept open for an extended perioda wire mesh grille protects the mic element & incorporates an internal wind screen to reduce popping noises from speechideal for desktop or shelf mounting, the integral microphone stand base is fitted with four, rubber isolated feet to reduce mechanical noise pick-upconstructed of high impact abs resin, the microphone is finished in a neutral dark gray with a prominent, orange push-to-talk buttonfeatures sleek, modern design fits today s high tech workstations,dynamic microphone element with a 600 ohm balanced output, prominent press-to-talk bar with convenient locking lever, auxiliary switch contact for mute or relay circuits,cardioid pattern with excellent ambient noise rejection,delivers a smooth & natural sound,four conductor attached cable,specifications directivity nidirectional, cardioid pattern, sensitivity 1 khz -58 db, frequency response 100hz-10khz, microphone element dynamic moving coil , impedance 600 ohm, balanced push-to-talk bar microphone normally closed mic element shorted *auxiliary switch contact normally open dry contact locking lever locks push-to-talk bar in 8220 on position, cable length attached 8.2 with stripped, tinned wireends, cable type 2-c shielded audio , 2-c aux switch ,microphone head finish zinc plated steel mesh, graybaked paint, stand base finish gray abs resin, dimensions w x h x d 3.9 x 8.5 x 5.9 , weight 0.97 lbs.