Rolex Explorer II

1971 spin-off of the Explorer adding a fixed 24-hour bezel and independent 24-hour hand so cave and polar explorers could tell day from night.

5 references

Reference	Variant	Years	Dial	Size
1655	"Freccione"	1971–1985	black	39 mm
16550	Not recorded	1985–1989	black or white	40 mm
16570	Not recorded	1989–2011	black or white ("Polar")	40 mm
216570	Not recorded	2011–2021	black or white ("Polar")	42 mm
226570	Not recorded	2021	white ("Polar") or black	42 mm