A dyno torch, dynamo torch, or squeeze flashlight is a flashlight or pocket torch which generates energy via a flywheel. The user repeatedly squeezes a handle to spin a flywheel inside the flashlight, attached to a small generator/dynamo, supplying electric current to an incandescent bulb or light-emitting diode. The flashlight must be pumped continuously during use, with the flywheel turning the generator between squeezes to keep the light going continuously. Because electrical power is produced only when the handle is squeezed, a switch is not needed. Dyno lights were issued to German Wehrmacht soldiers during World War II, and were popular in Europe during the war because the electrical power supply to homes was not very reliable. In addition to "squeeze flashlight", American soldiers often referred to such lights as "squeezy flashlight" or even "squeegee flashlight".