K&S Telescopic Tubing has a thousand and one applications, from crafting and hobbies to medical and industrial. Made in the USA, this high-quality round tubing can be used when doing electrical or woodwork, making prototypes and models, puppets, and so much more. - K&S Telescopic Tubing - Brass, Medium Telescoping Tubing Assortment, Pkg of 4, 12"K&s Metal Telescopic Tubing, ROUND BRASS MEDIUM - This assortment includes; 12" brass tubes measuring 7/16", 15/32", 1/2" and 17/32" in diameter.