Preston Innovation Stotz from £1.99 Refills and complete dispensers.
Stotz are a hybrid shot designed for use on larger diameter lines (they also work perfectly on fine diameters too). The wide groove makes placing them on the line quick and easy. Another advantage is the increased surface area that grips the line. This prevents damage and also stops the Stotz pinging off under stress. The flat ends of Stotz produce a neat bulk when they are grouped together.