A microlouver includes a periodic structure in which a transparent layer and a light absorption layer are alternately disposed with a constant, repetitive period. The modules have three, four or five pin receiving openings and are joined to one another by dovetail connectors to form an elongated body having the desired number of pin receiving openings. , after heating the SP having improved thermostability in 20 mM Tris buffer at 55\xb0 C. Furthermore, each indicia may form a plurality of indicia identifying a respective plurality of days, a respective one or more weeks, a respective one or more months, or a respective one or more years. In an alternative embodiment, a splitter group may also be arranged in front of the main group in place of the range or auxiliary transmission group.