This Omnidirectional condenser capsule is designed to fit the Monoprice Small-Diaphragm Condenser Microphones (PID 600700). The Omnidirectional capsule tends to have better low-frequency response and a smoother response curve across all frequencies than a Cardioid capsule.
Although in theory an omnidirectional polar pattern will pickup sounds equally well from all directions, the presence of the microphone body will tend to reduce a microphone's ability to pickup sounds from the rear as the sound wavelength approaches the diameter of the microphone body. Given that the diameter of the 600700 mic is about 7/8" (22mm), there will be a slightly reduced rear pickup at around 15-16 KHz.
An Omnidirectional polar pattern is well suited for use as an ambient room mic, as a vocal mic for multiple singers (e.g., a choir), and in situations where you want to pickup all the reflected sounds inside an small space.
This item is sold as one individual capsule.