Brand new Hitachi.LG (HL) GA31N slot loading 12.7mm high superdrive with SATA interface suitable for the late '09 and later iMacs.
Grab distance: 30mm
Note that iMacs use manufacturer-specific optical bezels. Fitting this drive as a replacement for a different manufacturer (i.e. Sony or Panasonic) you may need to trim several of the tiny tabs from the front edge of the bezel to ensure the drive sits correctly.