Small Brass Tube Assortment is also known as a Hollow wire Assortment. Small Brass Tube Assortment is a package of 5 tubes with outside diameter 2.00mm with a hole of aprox. 0.55 mm. All tubes or hollow wires measure approximately 3" in length. Small Brass Tube Assortments are most commonly used for making Bushings but can be used for a variety of clock repairs.