Stop wasting money on energy costs with Foam King Pipe Insulation. Foam King Pipe Insulation- Insulates hot and cold pipes: pre slit for easy attachment to your pipes. These help to prevent winter freezing and summer sweating. Great for reducing plumbing noise and to reduce heat loss. ID (nominal) 5/8inch wall thickness 3/8 inch fits copper pipe size 3/4-inch fits iron pipe size 3/8-inch R value = 2.2.