The model number decoding for solar water pumps is as follows:

4D indicates the pump is suitable for deep wells with a 4-inch diameter
PC indicates the impeller material is SS (Stainless Steel)
15 indicates a maximum flow rate of 15 cubic meters per hour
40 indicates a maximum head of 40 meters
110 indicates an operating voltage of 110 volts
900 indicates a power rating of 900 watts