The Captive Backlead MK2 35-g is a handy lead wire tensioner made by Fox.

The innovative design of this lead affondafilo incorporates a "gate" mechanic rather than a clip, that sometimes is not very reliable, in the phase of release if the wire is not stretched in the right way.

The lead is provided with a slot in which to place it during the fishing, which also allows you to adjust the length of the cord according to the depth of the water.
This line fluorescent is highly visible, very useful to distinguish the false touch on the part of the fish that pass close to the line.

The Fox Captive Backlead MK2 includes complete instructions included.