R25 sti

can anyone help....i have a blitz sbc i-d,the instructions are not to good.dose anyone know what the L in the top right corner is,when i first set the controller its there and after a run its gone.although its still on the other channels.also theres a small scale next to it,what is this.....i am going to ring blitz tommorow but thought id give you lot a chance first.....cheers r25sti.