Kicker SX digital amplifiers 900.4, 400.2, 650.1 all work and have just been in storage. These amps were in my competition vehicle back in the mid-2000s and they sounded amazing do not have a vehicle that I can integrate these in or I would keep them. Would prefer to sell all three in a package. 600 for everything or each- 900.4- 350 400.2- 250 650.1-350 No low ballers or Tire kickers serious people only please do not need your help selling or your negative comments these are old school equipment these amps are super heavy back when they made high quality stuff way better than all the new junk coming on the market.