This is a set of threaded pyramid cones that you can use to isolate your speakers or hifi component. They are very similar to BDR’s Pyramid cones but with a slightly smaller base diameter. BDR has a 1.618″ diameter while this has a 1.125″ diameter. Height is the same at 1″ with a 1/4″ x 20 threaded riser. BDR’s Pyramid cones sell for $20 each but here, you get four for $30. Price and listing is for a set of four. Set is new and is taken out for the pics you see here.