Erosion Control Snake Bag Gravel Wattles are designed as a first line of defense in roadway filtration and will trap particle sizes as small as 0.1 fine sand. Our Snake Bag Gravel Wattle is designed to form 6” gravel wattle 4’ in length and weigh approximately 50 pounds when filled with ¼” gravel. To increase their overall strength and durability, Volm Snake Bags are made of a high UV mono-filament weave.