Saradomin croziers are part of the Vestment set and can be found by doing level 3 treasure trails. To equip one, the player needs at least 60 Prayer. The crozier is equipped as a staff in the weapons slot. This counts as a Saradomin item, and Saradomin creatures in the God Wars Dungeon (barring the bosses) won't be aggressive to you if you are wielding it.
Prior to 24 March 2014 this weapon was a popular choice for low level pkers. As it's only requirement to wield was 60 prayer it allowed even level 4 accounts to wield croziers while having the accuracy of a level 50 weapon.The update however changed the crozier to be wieldable item, with only a prayer bonus. The crozier is also no longer classified as a weapon.