Shapton Glass Stone, 16,000 Grit, #50303.
210mm x 70mm, 5mm thick (total thickness is 10mm: 5mm of abrasive bonded to 5mm glass plate).
Note: This stone is not recommended for sharpening razors. The 10,000 grit is a better choice because it has a more narrow particle distribution, whereas the 16,000 abrasive has wider tolerances and so can produce coarser scratches. This is fine for sharpening most kitchen and other knives and tools, but not ideal for finishing razors.
Shapton GlassStones are very fast cutting and long-lasting. The ceramic abrasive is permanently bonded to a glass plate so the whole unit is very flat and very strong. The abrasive is extremely consistent and dense so you have a great feel and can produce very precise and clean edges, plus these have the convenience of splash-and-go sharpening (do not soak these stones).
The Shapton stone holder (sold separately) is designed to fit these stones perfectly and is quite heavy and tall, providing a great workstation. The more affordable Naniwa universal/adjustable stone holder also works fine for these stones.
Made in Japan.
Be sure to check out the Shapton FAQ.