Check the listing for details. Hybrid80 Jig Tooling. Condition: New. Listed at 14.99 USD. If you've decided to finish your own 80% lower receiver, you'll need the proper bits and end mill bit. Not to worry though; we've put together all the correct sizes you'll need into one kit. Includes:5/16" X 3/8" HSS 4 Flute Single End X Long Center Cutting End Mill, Qualtech (x1)3/8" High Speed Steel Drill Bit (x1)5/16" High Speed Steel Drill Bit (x1)5/23" High Speed Steel Drill Bit (x1) End Mill Bit Features:Size: 5/16"Material: High Speed SteelFinish: Uncoated (Bright)Flute Length: 2Overall Length: 3-3/4Shank Size: 3/8Style: Single End, SquareNumber of Flutes: 4Center Cutting: Non Center CuttingDecimal Equivalent: 0.3125Metric Equivalent: 7.9375mm---------- Shipped next business day! All parts are sold with the understanding that they will Be fitted, installed, and safety checked by a certified gunsmith. The seller is not liable for any property damages, injury, or death whatsoever due to negligence or faulty manufacturing issues. By purchasing this item you release the seller of any and all responsibility in your actions with these parts.