The factory keyless entry systems for 2007-2010 Hyundai Elantra cars use a 4-button remote with FCC ID OSLOKA-310T. There are lock, unlock and trunk buttons on the front and a panic button on the back. The current Hyundai part number for this remote is 95430-3K202.
See Hyundai Elantra remote at this link.
These systems require dealership programming to add a new remote.