99\% pure copper made to ASTM standard B-88. Type L is the standard wall thickness for pressure applications. Annealed for ready bending. I.D. measurements apply to type L tubing. Heavy wall for general plumbing and heating purposes. Available in 1/4", 3/8", or 1/2" x 20' coils. The boxed packaging of the Mueller short cut copper program provides for a clean and organized method of merchandising these items.