Stop wasting money on energy costs with Foam King Pipe Insulation. Foam King Pipe Insulation- Insulates hot and cold pipes: pre slit for easy attachement 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 1/2 inch, fits iron pipe size 3/8 inch, R value = 2.2 Safe for tempeatures from -90F to 180F degrees (-68C to 82C). Flame Spread: Class A ASTM E84; CAN/ULC-S102.2-M88 Smoke Classification: Class A ASTM E84; CAN/ULC-S102.2-M88