... aluminum2) Feature of casing Length : 130mm, 150mm, 160mm, 200mm, 220mm, 250mm Diameter: 20mm, 25mmMaterial of protecting case: brass, carbon ... steel or stainless steel3) Feature of the stem ... Length of stem: 50mm, 60mm, 80mm, 100mm, 120mm, 160mm, 200mm, 250mm, 300mm, ...