Rolex 216570 was in production from 2011 to 2021, a run of 10 years, carrying the 3187 automatic caliber in a 42 mm case rated to 100 meters.
The 42 mm fortieth-anniversary Explorer II, which brought the orange arrow hand back after twenty-seven years.
The full collector's file for this reference — variants, dial codes, and the authentication walk-through — is on the writing schedule; the specifications above are the permanent record.
The Explorer's fraud pattern follows its production lengths. On the long references, especially the 1016, dial generation is the real identifier and the serial alone settles very little: gilt, matte and service dials each belong to specific windows, and mismatched combinations are the most common problem in the market. On the 6350 the honeycomb dial carries a premium large enough to attract forgery, so that claim needs independent opinion rather than a seller's description. On the Explorer II, the 16550's cream dial is graded by tone and evenness, which photographs distort easily, and the 1655's orange arrow hand is a frequently replaced part. The Rolex serial lookup on this site covers every reference in this family.
Production windows and specifications compiled from documented collector references and period catalogs, cross-checked across independent sources; manufacturer records for this era are approximate by Seiko's own account.