Pre-cut aluminum and copper tubes in a range of lengths to match any tying/angling situation. Line tubes with included Micro tubing. Add standard drilled cones or beads if desired. Hook Holder tubing also included. Aluminum Tubes. 3/32" o.d. tubes sink slowly and drift naturally. Micro and Hook Holder tubing incl. 10 per pack. Copper Tubes, Large. 1/8" o.d. thick-walled tubes that take flies down quickly. Micro and Hook Holder tubing incl. 10 per pack. Copper Tubes, Small. 3/32" o.d. , low-profile copper tubes sink 2-3X faster than aluminum. Micro and Hook Holder tubing incl. 10 per pack.