A 2 inch Akhand Narmadeshwar Shivling is a sacred symbol that can be used for home worship and is considered to be very auspicious:
Benefits
Some believe that the Narmadeshwar Shivling can help with:

Eliminating the effect of planet Saturn
Achieving success in life
Maintaining cordial relations between husband and wife
Purifying negative energies
Promoting harmony and balance in one's life
Protection from malevolent forces
Removing obstacles