This is the Badger Paint Mixer [121]

BAD121 refers to the Badger Air-Brush Co. Paint Mixer, a battery-powered handheld tool designed for thoroughly mixing hobby paints. It features a two-position on/off switch, a detachable stainless steel mixing rod, and requires two AA batteries (not included). While effective for many paints, the mixing head's size may be too large for certain dropper bottles.  

Key Features
Purpose: To mix all types of paints, ensuring consistent viscosity and pigment dispersion. 
Design: A plastic, handheld unit with a removable stainless steel mixing rod. 
Power: Requires two AA batteries, which are not included with the mixer. 
Operation: Has a two-position ON/OFF switch. 

How to Use
Insert two AA batteries into the mixer. 
Insert the detachable mixing rod into the paint bottle. 
Turn on the mixer and run it to thoroughly blend the paint. 
Clean the mixing rod by running it in a bottle of clean water or brush cleaner after use. 

Considerations 
Bottle Compatibility: The 11mm impeller diameter of the mixing head may be too large to fit into some smaller dropper bottles, such as those from brands like Vallejo or AK Interactive.
Maintenance: Users may need to clean the dimple in the center of the mixing paddle to prevent paint buildup, especially when switching colors or paint types.