20' coils. 99\% pure copper. Annealed for ready bending. O.D. measurements apply to refrigerator tubing. Available in 1/4" and 3/8" x 20' coils. Mueller Industries dehydrated refrigeration coils are made to ASTM standard B-280. The copper tube is cleaned, nitrogen urged, capped (with standard yellow caps) and shrink-wrapped to an air tight seal.