The classic drip scale is the Hario VSTN-2000. It can also be used as a home kitchen scale.
The scale and timer can be operated with easy-to-understand controls. High-performance, stylish scales often have no written information, making it difficult to learn how to use them, but this one doesn't have that problem, and you can start using it the moment you open the box.
Coffee scales are sold for up to tens of thousands of yen, but basically all you need is a scale that can measure weight and time, so this Hario scale is often used in professional settings.
A timer is essential for stable drip, so why not add one to your coffee equipment?
