The Rycote TAC!T- XLR-3F to XLR-3M Barrel Adapter Filter with Integrated Third Order 18 dB/Octave HPF is designed to filter out infrasonics and low frequency noise below 60 Hz such as from wind, surface vibrations, and handling noise that could otherwise overload your microphone. The filter is built into a Neutrik XX-series XLR connector and requires a portion of a mixer's or preamp's phantom power to operate. The filter is symmetrically balanced so it can then pass phantom power to the condenser microphone while retaining a balanced signal.
Because it requires the microphone to draw phantom power through the circuit, the filter will not work with dynamic microphones and may slightly reduce the performance (in max SPL or self-noise) of high draw microphones such as those from Earthworks. Typically the front end filters of most live mixers are 6 or 12 dB/octave, so the 18 dB/octave filter in the barrel adapter will be more effective at cutting low frequency energy and is especially useful in applications where no external filter is available such as when sending the microphone signal into a camera.