Navagraha Yantra:

Navgraha Yantra is a combined Yantra for all the nine planets and is divided into nine squares, each one with a talisman representing one Planet. Navgraha is an extremely useful and beneficial yantra, since it's worship strengthens benefic planets and increases their positive influence and pacifies malefic planets and neutralizes their negative effect, navgraha yantra is recommended for all, particularly those whose planets are detrimental or malefic as per horoscope. Navgraha yantra should be worshipped life-long to ensure that you always get maximum advantages from the planets.