UltraTech 9454 Heavy Metal Removal Ultra-Filter Sock, 108" Length x 7" Width x 4" Height Heavy metal removal custom filter media blend helps remove zinc, lead, copper and other harmful, heavy metals Use in front of storm drains, around downspouts, in gullies and ditches or anywhere there is potential for harmful stormwater runoff Woven polymer casing allows water to pass through quickly while filtration media inside removes pollutants Units can be overlapped if longer coverage is necessary Looped ends allow units to be staked in place and also assist in transport