Which famous Levi's jeans model is commonly called the 'shrink-to-fit' model?

The Levi's 501 Original is the famous Levi's model commonly sold as shrink-to-fit denim.

Shrink-to-fit 501 jeans are sold untreated or minimally treated so the wearer can shape the garment through washing and wearing. The denim contracts during its first substantial wash, making the initial sizing and washing method important to the final fit.

This tradition is closely associated with the classic 501, but not every modern 501 product is shrink-to-fit. Levi's also sells prewashed, pre-shrunk, and stretch versions, so the product description must be checked before purchase.

The 501 is also distinct from the 505, 511, and 517, which have different cuts and historical design purposes. The phrase 'shrink-to-fit' describes a treatment and sizing method, not a separate company or a universal feature of every garment carrying the 501 name.