What will it be, a butterfly knife with a razor sharp edge or a trainer blade? The Marty McFly QBS-1 from Quartermaster makes it possible to have both while offering great flipping action. Their patented BladEXChange feature allows the user to remove the handles from one blade with a push button release, and quickly attach to another blade. The QBS-1 includes both a "live" tanto blade and a satin finished, dull trainer blade. Handles are bead blast finished titanium and include a pocket clip and titanium latch.