These capacitors will replace the 39,000 Mfd 40 volt capacitors in McIntosh MC2100, MC2105 and several other McIntosh units. The specs are MUCH better than original. These are 56,000 Mfd and the working voltage is 63 volts DC. I have installed several pairs of these caps and been very pleased with the results. Noise on the positive and negative rails decreased substantially. These are the same exact diameter as the originals. They are something like 3/8" shorter than the original. The polarity and the vent port match the old ones perfectly. Note, if you are installing these yourself you MUST be 100% totally SURE that the terminals are EXACTLY in the center of the chassis holes. The new ones do not have a high shoulder. I used small grommets to insulate the terminals from the chassis. I will provide a sheet detailing how I installed them. I feel totally comfortable in my installations. I will supply the "O" rings attached with a touch of super glue to make things easier.(Note: the touch of super glue is ONLY to keep the "O" ring in place to make the installation easier.) Please also note that the working temperature is 95 degrees C. Note: Each one of these will be tested prior to shipment. I cannot be responsible for incorrect installation. If in doubt about your capabilities I strongly suggest an experienced technician do the job for you. It takes under 30 minutes each. Since they are tested and unused I offer no warranty. You CAN return them at your shipping expense and must also reimburse me for my actual shipping expenses IF the tiny paint seals on the screws are not broken. The McIntosh parts department will sell you their replacements for $200.00 a pair plus shipping and insurance. I will deliver these to you via FedEx Ground at NO CHARGE TO YOU! They will be insured and packaged very well. I only accept PayPal or US Postal Money Orders. The figure of $218. is the factory charge for their parts plus an average shipping/packaging charge. Important note: I have been an "ebay sucker" for years now. I'm trying to break that habit." If you wish to check my 100% feedback my username is NIKKOS. Note: For those readers that might be embarrassed by buying at a bargain, I will be happy to take the price the factory charge for this product that EXCEEDS original specifications. If that makes you feel better.