Hand-powered torches have been around for ages. Essentially you repeatedly squeeze a lever that converts the linear motion into a rotational motion that drives a dynamo. The dynamo then charges an internal battery that allows the low-powered light (often LED-based) to light up for a few minutes or hours. However, the Mini Dynamo Massager Torch, rather bizarrely, adds a massage function!
The massaging torch will give roughly 3-4 minutes of massage after around 1 minute of cranking. I just wonder how much your hand will ache after cranking the torch for 1 minute! However, you get several minutes of lighting when cranking the torch to a full charge, how much time depends on how bright you set the light to. However, if you think you might need a massage in the middle of nowhere when you’re on your own, it might be useful!
Source: Coolest-Gadgets