The Wrangler style number associated with the original men’s zipper-fly model is 13MWZ.
The model began as the 11MWZ in 1947, when Blue Bell introduced Wrangler jeans designed especially for cowboys. The letters “MWZ” refer to men’s western jeans with a zipper, while the number changed when the denim specification changed. In 1952, Blue Bell renamed the 11MWZ as the 13MWZ to reflect 13-ounce-per-yard denim. That historical progression explains why 13MWZ is the canonical name attached to Wrangler’s enduring original Cowboy Cut design.
The style was engineered for riding: it used felled seams, rear pockets positioned for comfort in the saddle, flat or reinforced hardware, and a zipper fly. The 13MWZ remains one of Wrangler’s best-known products and is sold as the Cowboy Cut Original Fit jean. It is often confused with 11MWZ because that was the original lot number, but 11MWZ and 13MWZ represent the same influential lineage rather than unrelated brands or fits.