The simple cylindrical shape of our Barrel thumb turn blends in with many of our different styles of door levers & knobs, and the scallop on the underside of the turn provides additional grip.
There are two sizes of rose backplates available, enabling designers to choose between having a symmetrical size rose to that of a lever or doorknob, or having a smaller size. A smaller rose creates an aesthetical hierarchy between the main feature (lever or knob), with the more discreet feature being the thumb turn.