Detroit Speed, Inc. 31 spline axles are built to withstand extreme use. Engineered for high performance street, track events and autocross. Using high quality alloy steel, Induction heat treated and magnafluxed to insure quality and reliability. Using 1/2"-20 by 3" studs in GM (5 x 4-3/4") and Ford (5 x 4-1/2") bolt patterns. They come with Torino flange bearings already installed on axle. Sold as a pair (2) Lug Nuts not included.