Hyeonjachongtong is a cylinder-Type cannon ignited and fired by hand. This is the third largest of the four types of cannons and one of heacy weapons. Arrows called Chadaejeon and iron balls were fired. It had a range of up to 2,000 bos(about 3.6km) when an arrow of secen geuns(about 4.2kg)being fired. Its firing process was same as that of Cheonjachongtong. It has the Total lenght of 95cm, its barrel length of 60 cm and the diameter of its muzzle of 7.5cm(outer diameter of 16cm). It is made of cast iron.