ethiopian mat 5 star gold mining grass mat gold mining dredges mat diamond recovery mats Gold sluice rubber matting synthetic turf for mining 3 star grass, 26mm thickness, size 1x16 meters/roll, weight 70kg/roll 4 star grass, 28mm thickness, size 1x15 meters/roll, weight 80kg/roll 5 star grass, 30mm thickness, size 1x15 meters/roll, weight 93kg/roll