German Anker Tauchboot Delphin transaltes as Anchor Diveboat Delphin. This lovely toy requires 3 HP2 'D' cells, giving 4.5 volts, housed in the controller . The dial can be set from 0 to 3 in forwards and reverse direction. The submarine will dive on the higher speed , and maintain its depth on the lower speed. I have not tried this toy yet , but being German , I will be surprised if it doesn't work well. Approximately 11 inches long.