Ultimate Arms Gear Forged Front Sight 3/16 Hex Nut Driver Tool Glock Adjustment 3/16" Inch Nut Roll Stainless Steel Fits All Glock 17 19 20 21 22 23 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Glock Front Sight Adjustment Tool Fits All Glocks. 3/16" Nut Driver for Front Sight And Multiple Installation. Easy Precision Elevation Adjustments For Standard Glock Front Posts Enhancing Shooting Accuracy. Precision Machined Steel Front Sight Tool. Used by Builders and Gunsmiths Worldwide.