The present invention provides systems and methods to adaptively control amplifier target power to maintain signal launching power as per design in networks with wavelength selective switch -based reconfigurable optical add-drop multiplexers using micro-electromechanical system. Means to solve the problem An assembly box comprises: a frame 1 that is rectangular as seen from the top and whose four sides are formed from plate materials 11a and the like which are square as seen from the front; and a base 2 that has a placement plane 2a for the frame 1 and guides 21 and the like for supporting the plate materials constituting the frame 1 on the placement plane 2a. , characterized in that the polymerization is carried out in the presence of one or more copolymerizable surfactants in agreement with the formula described below . The amine species of c) is in complex with the precursor monomer unit. The concave outer faces and the convex gripping portions form a non-smooth outer periphery of the peripheral wall portion to allow firm grip by a user.