The information on the back or your remote will indicate how to buy the correct remote. The first thing to notice is the facility code. This is the number such as FC30, FC31, or FC32. This code must match the code that you are ordering or else the remotes will not be able to be programmed.
The second thing to look for is the bit configuration. Most ClikCards come in 30-Bit configurations. This is most commonly indicated with the 30-01 in the lower left hand. If this is not your bit configuration then you will most likely need to special order them.
The next thing to look for is the number in the lower right corner. It will most likely be two letters followed by three numbers. The two letters indicate the type. A KR, such as KR295, indicates Keychain Remote. A VS, as in VS295, indicates Visor Remote. The three numbers afterwards indicate the clikcard transmitters frequency. The most common frequency is 295 MHz, although Sentex also manufactures 303 MHz versions. A 295 MHz frequency remote will not work with a 303 MHz system, or vise-versa.