A Medium Sized Naniwa Flattening Stone
The Naniwa Pink Flattening Stone measures 210MM x 55MM x 25MM. If you measure in inches that is roughly 8-1/4" x 2-3/16" x 1". This makes it larger than the A-102 Naniwa Flattening Stone, though not as large as the A-120 Extra Large Naniwa Flattening Stone.
Pink Aluminum Oxide
The Naniwa A-103 Flattening Stone is made of Pink Aluminum Oxide. Pink Aluminum Oxide is harder and more durable than more familiar White Aluminum Oxide, which is used in many water stones.
There is a reason Naniwa chose Pink Aluminum Oxide for this flattening stone. Most flattening stones are made with Silicon Carbide, which is a very jagged particle that cuts aggressively, but which is also brittle and breaks down quickly. Pink Alumina doesn't break down as quickly as Silicon Carbide, but still maintains a good aggressive cutting speed. This combination of cutting speed and durability, results in a hard wearing flattening stone that retains its shape well.
Use with Plenty of Water
Soak the flattening stone before use, and soak or wet the water stone as appropriate. Place the water stone on your work surface or hold it in your hand and then rub the Naniwa Flattening Stone over it until the water stone is perfectly flat.
Made in Japan.
Questions about flattening water stones? See out article How to Flatten a Water Stone.