These are a pair of refoamed HD(770/880) that will work fine in Amy HD Marantz ot DS version using a 12 in woofer. These did not get the traditional foam as the composite paper is beginning to break down with age, this type of foam fit better. I have check these woofer , mounted in a pair of 880 cabinets, VOM, and an RC oscillator. DCR is close to 8 ohms, the sound was equal throughout the range of the RC oscillator. I am leaving the pigtails on for convenience.i am including  the aluminum beauty ring , but not the screw. . Doe to the Age these are sold AS ID with no warranty implied . Priority mail will be used for the lower 48 states. Any questions , please message .NO RETURN on speakers.