The Speedmaster 57 is a modern ode to Omega's first generation of Speedmasters. It features a case with straight lugs and a bezel with the tachymeter scale engraved. The same features were found on early versions of Omega's iconic chronograph, while later models feature the swirling 'lyre' lugs and a bezel with separate inlay still in use today.
Reference 331.53.42.51.02.001 has a yellow gold case and an alligator strap. It is powered by the 'deluxe' caliber 9301.