This
is the same tether that comes with your SierraBlaster System. The
tether is important for safely securing the Blast Heads and a
must for inverted blasts. For inverted blasts the elastic
tether can be adjusted to impart cross tension on the Blast Head
creating more friction between the borehole and the Blast Rod thus
holding the Blast Head in the borehole even when inverted. This
is another component that may become damaged while blasting so it
is a good idea to have a few extra.