The black Shure R183BB is an omnidirectional mic cartridge compatible with all Microflex and WL series microphones. The modular design of the MX and WL series allows you to swap cartridges and use a different electret condenser microphone capsule without having to purchase an entire mic. The R183 features a forgiving omnidirectional polar pattern that picks up sound from 360° around the capsule, helping to provide consistent levels even when the talent turns away from the microphone.