Auralex U-Boat Floor Floater (each)

These are extras from a studio build and brand new.  Some have duct tape residue on one side they picked up in storage, does not affect performance.

From the Auralex site:

With the help of U-Boats, a floated room features improved transmission loss (isolation) and low frequency definition.

Auralex UBFF U-Boats are among the industry's most affordable solutions for floating floor installations. Made of a specially-formulated rubber U-shaped channel, U-Boats are used to support framing members and isolate them from the surrounding structure. With the help of U-Boats, a floated room features improved transmission loss (isolation) and low frequency definition. It's easy to figure how many U-Boats to underlay: just multiply the total square footage of the area you want to float by two thirds; the resulting number gives you the approximate amount of U-Boats you'll need. U-Boats are the industry's most affordable floating solution and are much easier to use than those exorbitant "pucks" that have been used in the past. To get the biggest benefit from U-Boats, install your joists 12" o.c. instead of 16" o.c. & use a U-Boat every 12" or so.