Shani Yantra is very effective in curtailing the malefic effects of planet Saturn. ... This Yantra is used to propitiate an afflicted Shani and helps tone down difficulties that you may be facing. When Saturn is malefic in a horoscope, in transit or causes Sadesati, use of Shani Yantra is very beneficial.
Shani Yantra/ Saturn Yantra is used to pacify an afflicted Shani/Saturn and achieve Rajayoga through complete blessings of Shani