Curious if anyone here knows what these stats mean?
Can you tell what grit it is etc?

[Max size] 85*140*22mm (25.4mm=1inch)
[Net Wt.] 552g ;approx. equal to 1 2/9lb (454g=1lb)
Hardness/Grit per hardness/Abrasive pow./Lightness of touch (H1=softest ,H5=hardest)
HGAL=4/max/max/max ...Honyama stones born in central Kyoto city are known as the highest class plates
Thanks for any insite