Please check the images for each size. Regarding the orange tab models like 646 and 684, the differences in details due to the different eras are mainly in the zippers. Unlike the 501, the early 66 models don't have single-stitched back pockets. Extremely few were manufactured with Line 7, and those are the ones with single-stitched back pockets. There are no Line 7 productions for the 684. All 646 with the number 2 stamp were Line 7, up to around 1975. Line 7 with the number 4 or 8 stamp are seen in the early models. A 1972 646 made on Line 7 (the same era as the 66 Big E for 501) instead of the usual orange tab Line 8 production line. Sleek stamp. Differences from the usual orange tab Line 8 manufactured 646: Outseam with a split seam Inseam single stitch Side seam Back pocket single stitch Black bar tack on back pocket The sewing method of the pocket's sleek is also different. Sleek stamp does not have size notation. (Based on actual measurements, it seems to be W30 L32) Made in May 1972, small "e" Talon 42 Number 4 stamp Original chain stitch One belt loop has some wear Slight wear on the inner thigh 36 inches 91.44 cm 35 inches 88.9 cm 34 inches 86.34 cm 33 inches 83.82 cm 32 inches 81.28 cm 31 inches 78.74 cm 30 inches 76.2 cm 29 inches 73.66 cm Levi's 684 bell bottoms, flares Outdoor festival, 70s