Check the listing for details. Muncie 4 Speed M20 M21 M22 M23 BRONZE Surface Thrust Washers set. 1 INCH. Condition: New. Listed at 17.95 USD. Muncie 4 Speed M20 M21 M22 M23 BRONZE Surface Thrust Washers set for 1-INCH countershaft. We now carry the same set for the 7/8" set. Includes:2 Countergear washers for 1" countershaft1 Forward reverse idler thrust washer.New - Steel backed bronze, replaces cheap steel washers offered in inferior rebuild kits and hyped cast washers.BEWARE OF EBAY SELLERS SELLING COPIES WITH POOR FEEDBACK These are steel backed and not cast. Much stronger than more expensive cast washers advertised as being better. Race proven and used for years by Muncie Builder and book author Paul Cangialosi. Remember these washers are submerged in oil and your whole surface area should be dimpled are designed to allow oil to enter your needle bearings and maximize an oil bearing surface over the whole washer not just 3 grooves.