This is a smaller version of the famous Stow bobbins, which were developed on the banks of Elstow Lake and have been used by many members of Team Korda for years. The principle behind this bobbin is that it can be fished with both tight and slack lines, and when you get a take, the line releases from the clip on the side of it.

For that to happen the stainless steel ball chain which it is fitted to needs to be the same length as your bite alarm, and a detachable connector system allows you to easily adjust it so that it is compatible with any buzzer (it comes set at the correct length for use with something like a Delkim, or similar sized alarm).