The Ehpro Armor COD Mech MOD comes with SUS303 stainless steel construction. The Ehpro Armor COD is compatible with a single 21700, 20700 and 18650 (with an included adapter) battery. The Ehpro Armor COD supports a minimum coil resistance of 0.1ohm too. The Ehpro Armor COD feature shield fire button with display, so you are capable of reading the voltage data.