Like new FetHead Phantom. For condenser mics that require 48 phantom power. Perfect for mics like the Lauten Audio LS208 that are great mics but could use more gain up front. Description from Triton:

FetHead Phantom is an ultra-low noise, high quality, in-line microphone preamplifier. It provides improved sound for condenser microphones. Small, compact, but powerful, Fethead Phantom utilizes tried and true FET technology to deliver up to 18dB of clean boost. No more cranking your mic preamp and adding unwanted noise to get your microphone to an acceptable volume. Boost your microphone!

• Adds up to +18dB clean gain for condenser mics
• Reduces noise floor, avoids cranking main preamp
• Uses 48V phantom power and passes it to microphone

Which microphones benefit: FetHead Phantom is specially designed for condenser microphones. It works very well with all condenser microphones. FetHead Phantom is also an indispensable tool for mobile recording and a real upgrade for camera microphone preamps, because it lowers the noise floor.

Operation: Your Fethead Phantom will latch straight onto any XLR equipped microphone, or anywhere else in the signal path between microphone and preamp/mixer. The electronics are housed in a robust metal chassis with a balanced female XLR input and a balanced male XLR output, rugged enough for use at home, in the studio or on tour.

Phantom power distribution: FetHead’s Phantom circuit uses 48V phantom power but also passes it on from its input to the microphone. Your condenser mic is powered with the same phantom power.