Polymer compositions comprising a polymeric substrate and an effective stabilizing amount of a synergistic mixture of a nano-scaled filler and at least one additive selected from the group consisting of the hindered amine light stabilizers are effectively stabilized against the deleterious effects of oxidative, thermal or light-induced degradation. The system determines the position of the second transceiver. The second set of opening includes a plurality of elongated holes extending through the plate transverse to the longitudinal axis of the plate. As the door is closed, the cam rotates through an angle thereby lifting the latch bar until the upwardly extending finger of the hook can move through the opening of the latch bar. The data is reconstructed responsively to the first and second output storage values.