Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Rolex Daytona
Table title:
Original series
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Years </th><th colspan=1 rowspan=1 > Reference </th><th colspan=1 rowspan=1 > Calibre </th><th colspan=1 rowspan=1 > VPH </th><th colspan=1 rowspan=1 > Bezel </th><th colspan=1 rowspan=1 > Oyster </th><th colspan=1 rowspan=1 > Notes/Features </th></tr>
<tr> <td colspan=1 rowspan=1 > 1963–69 </td><th class="highlighted"  colspan=1 rowspan=1 > 6239 </th><td colspan=1 rowspan=3 > 722, 722-1 </td><td colspan=1 rowspan=3 > 18,000 </td><td class="highlighted"  colspan=1 rowspan=1 > Engraved (stainless steel) </td><td colspan=1 rowspan=1 > No No </td><td colspan=1 rowspan=1 > Earliest model carries extra tachymeter engraving at 275 units/hr. </td></tr>
<tr> <td colspan=1 rowspan=1 > 1965–69 </td><th colspan=1 rowspan=1 > 6240 </th><td class="highlighted"  colspan=1 rowspan=2 > Black (acrylic inlay) </td><td colspan=1 rowspan=1 > Yes Yes </td><td colspan=1 rowspan=1 > First appearance of optional metallic dial finish. </td></tr>
<tr> <td colspan=1 rowspan=1 > 1965–69 </td><th class="highlighted"  colspan=1 rowspan=1 > 6241 </th><td colspan=1 rowspan=2 > No No </td><td colspan=1 rowspan=1 > All variants include "Daytona" printed on dial. </td></tr>
<tr> <td colspan=1 rowspan=1 > 1970 </td><th colspan=1 rowspan=1 > 6262 </th><td colspan=1 rowspan=4 > 727 </td><td colspan=1 rowspan=4 > 21,600 </td><td colspan=1 rowspan=1 > Engraved (stainless steel) </td><td colspan=1 rowspan=1 > Produced for one year only. </td></tr>
<tr> <td colspan=1 rowspan=1 > 1971–88 </td><th colspan=1 rowspan=1 > 6263 </th><td colspan=1 rowspan=2 > Black (acrylic inlay) </td><td colspan=1 rowspan=1 > Yes Yes </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1970–72 </td><th colspan=1 rowspan=1 > 6264 </th><td colspan=1 rowspan=1 > No No </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1971–88 </td><th colspan=1 rowspan=1 > 6265 </th><td colspan=1 rowspan=1 > Engraved (stainless steel) </td><td colspan=1 rowspan=1 > Yes Yes </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What was the successor of the Rolex Daytona 6239, and what were some of the improvements over the predecessor?
Answer:
Rolex Daytona´s 6239 were succeeded by the 6241, which replaced the engraved stainless steel bezel with a black acrylic bezel.