Polymer80 P80RJ556U Mil-Spec AR15 Lower Universal Jig Polymer Polymer80's AR15 Universal Jig Is Compatibility With Mil-Spec 80 Percent AR15 Lower receivers No Matter Whether They're Polymer Or Metal. The Universal Jig Is Designed With a Super Rigid Long-Fiber Nylon Composite, Which Allows You To Utilize The Jig Up To 3 times. The Jig Also provides a Stable Platform For Milling, And Therefore encompasses The Entire AR15 Lower Receiver. This Kit Includes a Two Sided Jig, Three Trigger guides, 9mm HSS End-Mill, And Drill Bits (5/16Th, 3/8Th, And 5/32Nd). Type: Jig Material: Polymer Bit Type: Various Gun Type: AR-Style Rifles Gun Model: AR-15