Dear sir, FM1 ,FM2 FM3, is to increase the memory of your Radio set. Say there are 18 stations (Radio Station ) in your area but Radio Set has 6 buttons i.e. 6 stations it can memories. However the balance 12 stations can be memorized in FM 2 and FM 3 having each FM six stations in memory. Therefore all the 18 stations can be selected with in one of the FM bank i.e. FM1, FM2 or FM3. Race being the same but scooter has three gears.