If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.
When you google this you will see there is quite som information written on these hones.
I will not repeat this But I will show you mine. I have two boxed ones
a strop on one side and a hone in the middle with room for a razor on the other side
Size: 98 x 30 x 10mm weight: 80gr. Density: xxgr./cm³ / Estimated grit size: very fine <12k Usage: only with water, never use oil! Color: green-grey, dark-grey, sometimes going in brown, mottled…