Roberts First Step Premium 3-in-1 Flooring Underlayment - 315 Sq Ft

No problems with the Styrofoam balls when cutting as they're sandwiched between the two sheets of plastic, and the stuff does tear if you hit it with a hammer, but seriously you just hit it with a hammer plus it's an easy fix with a little bit of duct tape

Much better pricing than the red stuff found in the local hardware store. Same quality.

Enought left over to do another room! Item described perfectly! Works well!