The Electro-Voice Model 654 is a dynamic mic with uniform frequency response from 50 to 16k cycles per second. Impedance is through a recessed switch in the microphone stud, selectable to 50 or 250 ohms with the line balanced to ground and phased. Its polar pattern is essentially omnidirectional, directional with rise in frequency. Dimensions are 1-3/32" diameter and 10-1/16" length; weight is 16oz.

Electro-Voice Model 654 frequency response

Electro-Voice Model 654 polar pattern

Electro-Voice Model 654 specification sheet