A low-pass filter transmission line with an integral electro-absorption modulator is described. In one aspect, interface buses group the data lines according to groups of bits, and include group-enable lines to convey a representation of which groups of data lines are active for each data transfer operation. The key that is inserted in said receiving device cannot be twisted while being movable in a longitudinal direction into at least one defined raised position. The assembly also includes an upper member and a lower member operatively joined to define a plurality of discrete fluid conduits, and a sealing film to adhere the bonding surface of the IC to the lower member, so that the conduits and supply channels are in fluid communication with each other. The drive unit is arranged to be used to drive the second lens unit with respect to the first lens unit, and is fixed to the first lens unit.