GSM is grams per square metre. It is not tensile strength and it is not a slope rating. A 900 GSM mat can open if the weave is loose and the fibre is short. A 400 GSM mat can hold a gentle batter if a log sits at the toe.
The geotextile enquire set is 400 / 700 / 900. Mills spin a wider range; that is not a reason for forty URLs. Blankets are not woven mats. The log is the other half of the same system: mat on the face, log at the toe.
Loadability is the real 40’HC count after wrapping, not a brochure number. We do not print durability years. How to read the floor is on Coir quality. The sendable brochure is /coir/catalog/erosion.