is needed to hold a pane in place optionally for any unit according to the present invention structure to hold a pane in place and or tongue channel structures may be used only on a frame side or a frame 39 s sides or only on a frame 39 s end or ends using a magnetic strip pane mount or tape or both to hold a pane in place in certain embodiments of the present invention the entire periphery of a pane is covered either by portions of the magnetic strips or by tape so that the entire periphery is sealed to air flow it is within the scope of the present invention to provide a shutter e g but not limited to the shutter 30 fig1 a or a shutter 216 fig9 a with a pane attached adhered and or connected to a shutter instead of or in addition to a pane of a shutter unit e g but not limited to a pane as in any of fig1 a 9b fig1 shows a shutter unit 10 a like the shutter unit 10 fig1 a and like numerals indicate like parts with a pane 300 connected to a shutter 30 a like the shutter 30 fig1 a with bolts 301 and nuts 302 the bolts 301 are sufficiently long that movement of the louvers 34 is not impeded optionally the pane 50 is deleted and optionally in a unit according to.