yes there shit but.............

i understand that (or was told) narrow band 0.1-1volt sensors can only read roughly 14.0:1 (1.0v) and 15.4:1(.1v) hence useless for any on boost fuelling, So why do companies that make displays ie Lumenition have a led for lambda 1 AND a led for max power (12.7?) yet state a 0.1-1v sensor is what to use ??????