This is the Western Range Tufted Grass Mat (one 11.75" X 7.5" sheet)
from Bachmann Trains.
Super detail your layout in any scale with a wild grass landscape. This ready-to-use Tufted Grass Mat starts with a lush covering of 5mm static grass on a flexible foam base. Depending on the mat style, various layers of foliage, turf mounds, leaves, and grass tufts are added for an incredibly lifelike appearance. Use whole for large areas or cut into patches to create random areas of groundcover. Simply apply with white glue or spray adhesive to your base platform or wherever you want grass to grow. Professional, realistic-looking scenery has never been easier!