The prefix LA is followed by the Class in which the equipment is approved. 'LA1' for Class 1 and 'LA3' for Class 3.
Class 1
equipment is without operational restrictions and may be used for VFR and IFR flight in any airspace, provided that it has adequate frequency coverage and number of channels for the particular area in which the aircraft is to operate. It may also be used for any of the purposes specified for Class 3.
Class 3
communication equipment may be used outside controlled airspace under VFR and IFR, to communicate with airfield ATCs where it is not a condition of use of the airfield that R/T equipment be carried, or for communication with the Flight Information Region Controller. It may also be used within controlled airspace under special VFR or under Special entry/exit lane procedures. Class 3 navigation equipment may only be used outside controlled airspace under VFR or IFR, or 'Special VFR' within controlled airspace.
NB: For equipment installed in aircraft not exceeding 5700kg