It is a dead stock of Levi's 501xxc manufactured in September 1998. 555 on the back of the button. Red tab (one-sided big E). It is the last Cinchback model of 501xx in 37 to 40 years. It is made in the United States, made in the Valencia factory using 14 oz xx denim using an old loom from Corn Mills.
Unlike general denim made with modern looms, you can expect a good color fading with a good atmosphere.