Offered here is a set of three IsoAcoustics Orea series Bronze (8-lb each capacity) equipment footers. I purchased them new from an Amazon vendor last August and was using them under a power conditioner, since replaced by a newer unit which does not require them. You'll see scuff marks on the rubber surfaces from where the equipment was sitting, but I don't believe this will have any impact on performance. The total weight of the component you place on the three footers should not exceed 24 lbs, according to the manufacturer. 

There is an excellent set of Q&As on the manufacturer's website. These devices have been well reviewed and I use them under my phono stage and preamp as well. Original packaging (which is beautiful) is included. Here's a review from Stereophile.

USPS Priority Mail postage to US addresses is included in the price.

Manufacturer's description:

Eliminates parasitic vibrations and provides greater sound clarity and focus. The OREA’s are ideal for electronic components including Amplifiers, DAC’s, CD Players, Speakers, and Turntables. Made of machined stainless steel, these isolators have a low-profile design to minimize any increase in height.

Each OREA model is designed with a different weight capacity. They each have a coloured ring on the bottom isolator that denotes the model and weight capacity. The OREA series are packaged individually to allow greater flexibility when determining the number of units to use. We recommend a minimum of 3 units under each component, depending on weight.

The upper flange of the OREAs is designed to provide a suction-cup-like effect and adhere to the underside of the component, while the lower flange adheres to the supporting surface. All the energy is managed within the core of the OREAs, which are tuned to work within specific weight ranges. This results in greater sound clarity and a more open soundstage providing authentic, three-dimensional sound.

The existing feet on an audio component may connect well and fit nicely around the perimeter of the OREA isolator. Alternatively, you may get better performance by either removing the feet entirely or placing the OREA’s beside the existing feet to have them connect directly to the chassis or base of the component.

Weight Capacity

The weight capacity per OREA isolator is as follows:

OREA Bronze - 8 pounds (3.6 KG) per isolator

The OREA’s are designed to be used in multiples to match the weight of the component or speaker. The total weight capacity is calculated as follows:

Total Weight Capacity = [Weight cap. per isolator] x [Qty of Isolators]