This Silicone Tube has a multitude of different uses, but the main one is holding the hair in place on your hook. It comes in two versions 0.5mm and 0.75mm to ensure that it will fit any hook size and diameter of hair material, trapping it securely but sliding up the shank if it needs to once a fish is hooked. It is Weedy Green in colour and there is 1.5m of it in a pack.