Welcome to my auction. This is one pair of equipment for the speaker ports on the Marantz Model HD770 and HD880 stereo speakers (may also fit other models in this Series). These Vari-Q port plugs originally had closed cell foam between the circular discs. Once the foam plug was inserted into the speaker port - it would seal the port - changing the speaker housing from being a Ported Cabinet to a Sealed Cabinet. This means that it can work in a closed and open system. All Vintage electronic devices are sold AS IS and have no warranty of any kind. The buyer accepts responsibility for all repairs, renovations and refurbishments of any equipment purchased. Returns will not be accepted for this product. This pair or Vari-Q gear is in very good condition and quite rare. The photos are taken by me and show the authentic condition. The subject of the Auction are the Marantz Bass Plugs themselves.