Aqua Flies Poly Tubes are formulated from a temperature stable polyethylene, meaning in near freezing conditions the tubes will not break. With colors to choose from, you can give your tube flies a new look. Tie a fly directly on the tubing or use it as a liner for metal tubes or weights The 1.8mm tube is the right size to tie trout flies or lightweight steelhead flies, such as marabou tubes The 3mm size makes a great platform for tying larger steelhead flies, such as Intruders or saltwater streamers The inside diameter of the 3mm will accept the 1.8mm tube perfectly Add an Aqua Flies Tube Conehead to your fly by using the 1.8mm tube as a liner for the 3mm tube. A drop of super glue will hold the smaller tube in place, but to make for a more secure fit, cinch down on the tying thread so the larger tube is bound down onto the smaller tube. Hold the cone in place by holding a flame close to the end of the tube so it melts slightly and creates a collar Ultra Tubing will accept hooks up to a size 2 1.8mm (1/16″) outside diameter 3mm (1/8″) outside diameter