This was the hand made dhoti Gandhi wore durring his fast for non-violence and was snagged after he was assassinated; it radiates "pure peace".
It is used in "A New Hope " as an attempt to defuse the House of Commons Masonry Bomb and save the warehouse. However, the dhoti was rendered ineffective since the bomb relied on a person's hatred to activate. The dhoti was then used to cover Walter Sykes and allowed him to gain absolute peace, thus rendering the bomb inert.
It's unknown if this artifact kills its' user as there's still debate over what exactly caused the death of Walter Sykes.