The activated carbon base shall be coal based with a carbon tetrachloride activity of no less than 60% and retentivity of no less than 35%. The hardness shall be no less than 95% with an ash content of no more than 15%. The particle size distribution shall be a nominal 4.0 mm diameter and a length of 6.0 mm. The mean particle diameter shall be a minimum of 4.7 mm. The iodine number shall be a minimum of 1000 milligram per gram and a surface area of no less than 1000 square meters per gram. The impregnate shall be a 5% potassium hydroxide on the pellet coal based carbon. The moisture content of the impregnated carbon shall not exceed 15%. The hydrogen sulfide breakthrough capacity shall be no less than 0.16 grams per cubic centimeter.