It is intended for installing in blast-hole or borehole with a purpose deduction of a hole loa in rising blast-hole or borehole. It is allowed use the plug instead of inert stem. It is made four standard sizes for blast-hole and borehole in diameter:
   from 28 mm up to 32 мм
   from 38 mm up to 45 мм
   from 45 mm up to 55 мм
   from 65 mm up to 100 мм