KATSUICHI DECOY Tuning Tube T-4 is a heat-shrinkable tube designed to be fitted over the shank of a jighead or jig hook and shrunk with heat to help reduce soft-plastic lure slippage. It functions as a worm keeper to hold a soft plastic lure rigged on the hook. Available in inner diameters from 0.8 to 3 mm, it can be selected to match the wire diameter, from fine-wire to heavy-wire hooks.
The shrink ratio is approximately 50% of the original diameter. To use, slide the tube onto the hook shank, position it, and apply heat with a lighter or similar heat source to shrink it. Use caution when heating, as applying a flame directly for too long may melt the tube. Since the hook can become hot during heating, securing it with pliers or a vise is recommended. The 0.8 mm, 1.0 mm, and 1.5 mm sizes are 1 m long, while the 2.0 mm, 2.5 mm, and 3.0 mm sizes are 80 cm long. In addition to holding soft plastic lures on jigheads and jig hooks, it can also be used to protect the connection point of assist hooks for light jigging.