Use one of the following entries with the giveitem self code. Note: The game appears to have only one type of Omnitool. For example, enter giveitem self 10 omnitool manf_aldrin_omniTool as a code.

Manf_Aldrin_OmniTool
Manf_Ariake_OmniTool
Manf_Armali_OmniTool
Manf_Elkoss_OmniTool
Manf_Serrice_OmniTool
Manf_Sitta_OmniTool
Manf_Spectre01_OmniTool
Manf_Spectre02_OmniTool
Manf_Spectre03_OmniTool