Cylinder buttons in the place of standard button

Style of button 

value="group_$id_attribute_group"} Volta line - round chrome-plated notched knob value="group_$id_attribute_group"} Rio line - round knob - brushed stainless steel value="group_$id_attribute_group"} Rio line - triangle knob - brushed stainless steel value="group_$id_attribute_group"} Danube line - imprint button - satin aluminium