replacing/upgrading broken thumb shifters on a mtb

[Bob_Coulson]

Hi, i have an Olympus Spectrum MTB which a bought a couple of years ago, it has an 18speed falcon index system. It currently has thumb shifters on and i had an accident on it the other day and it broke one of the levers off. I have been looking for a replace it but cannot find any for a falcon index system. Can anyone tell me if i can replace the shifters without needing to replace the system? In a booklet i got with the bike it has an installation guide for MRX grip shifters, i found some of these on ebay but the seller had them described as setup for Shimano index. with my lack of Knowledge of the different systems i am wary of ordering them in case they are the wrong ones.
If anyone can help me with this i would be very grateful.
Thanks very much, Bob

 

[TheDoctor]

I'll lay money that the Shimano compatible ones will do it.

 

[fossyant]

Any shimano 8 speeds will do it, or grip shift.

 

[RecordAceFromNew]

I agree with the Doctor, chance is any current 6 speed Shimano compatible ones will do it.

If the OP wants to be sure, knowing the the make and model of the rear mech (if that for the shifter is not available/clear) will help to confirm re Shimano or Sram 1:1 compatibility.