Prong Lifter Stone Removal Tool - SFC Tools - 53-144 This stone prong lifter is designed to gently pry prongs from stone settings when remounting, resetting or re-tipping. There are 7 prong slots which range in size from 0.58 mm to 2.34 mm. Made of blackened steel. Overall measures 4.5 x 0.46 x 0.116 (114.3 x 11.8 x 2.9 mm).