The Hart & Cooley R4.2 F204 sleeves are a pack of 3 tubular pipe insulation rolls, each measuring 14 inches in diameter and 5 feet in length. Made of fiberglass material, these flexible sleeves are suitable for use in various industrial plumbing and heating systems such as boilers, water pumps, air conditioning units, water tanks, and refrigeration systems. Manufactured in the United States, these sleeves provide insulation and protection for pipes, helping to maintain optimal temperatures and energy efficiency.