Although the Explorer series have been in existence since the 1950s, the modern Explorer evolved in 1989 with the release of the 14270 that introduced Sapphire crystal, gloss dial with white gold surrounds to the markers, a redesigned 36 mm case and the 27 jewels Cal 3000 movement. The 114270 followed in 2001, upgraded with the 31 jeweled Cal 3130 and solid end links to the bracelet, but retaining the 36mm case and pressed clasp.
Another major upgrade to the Rolex Explorer range came in 2010 with the release of the 214270. The most obvious change being the increase of case diameter from 36 mm to 39 mm. The movement was also upgraded to the Cal 3132, along with changes to the dial, bracelet and clasp.