Tuning Key Robo Key 4x Speed

The structure is ratchet-type (switch direction at the gray part in the center). When turning, if you hold down the black part with your other hand so it doesn't turn together, it engages a 4x speed mechanism.
It can be turned at 4x speed, allowing for smooth head changes. When tightening, unlike with electric tools, you can feel the torque by hand. Also, compared to things like bamboo helicopters, it's not bulky, making it excellent.
I personally switched to the bamboo helicopter style immediately after buying this, so it doesn't have its original packaging, but it's almost unused.
The selling price at a certain S house was ¥2,980 (tax included).