These drains need to be replaced with an VGB compliant MDX2 cover. If you are not re-doing the finish of your gunite pool, or you have a vinyl liner pool, you need to have the MDX2 Retro, part # 004-202-2221-XX, installed by a pool company to meet the new VBG Pool and Spa Safety Act.  .  On vinyl pools you may also need new gaskets and screws.
You will also need to replace the cover of the SDX with a new SDX2 cover, part number  005-252-2097-XX.
The MDX2, MDX3, SDX/SDX2, Super Flow 360 and Buzz Top covers must be replaced within the time engraved on the cover install.