Up for grabs is an exceptionally rare and extremely beautiful early Rolex Explorer, reference 6610, circa 1956. However, what sets this particular 6610 apart is that one small line of text under “Explorer”, known as “red depth” rating. These red depth ratings are only seen on a handful of 6610s produced for a short period of time in 1956, with serial 11xxxx, a true novelty. This particular Rolex Explorer “red depth” is in excellent vintage condition. The case appears unpolished, with thick and even lugs. The dial is very well-preserved, with light aging from the radium throughout. Following that, the original radium lume remains present on both dial and hands, aged to a nice pale yellow color. The watch comes fitted on a later Rolex Swiss Jubilee bracelet, dated to 1964, and has reasonable stretch for an old Jubilee, and will fit a large wrist.