The ways of mark the dimension:DSG-Type OD/OL/HZ/CZ/D/E/F/G Order sample: OD=25mm, HZ=300mm, CZ=200mm, OL=700mm, Resistance=1.2ohms. Please specify as: dia25x300x700mmx1.2ohms DSG—type Minimum size available:12mm Diameter When you place order, please tell us following data: a).Outer diameter (OD) b).Length of Hot zone (HZ) c).Length of Overall (OL) d).Resistance (at 1050℃ +/-50℃)