This is an amazing mic system that I am reluctantly selling. I've had it for 20 years, and it hasn't been used in 5. I have tested both caps recently and they sound as lovely as the day I bought the system. I can't find much info online re: specs but here's a pretty in depth review. https://www.mixonline.com/technology/field-test-korby-kat-4-tube-microphone-system-369527
