Thunder Helm Version X (雷のヘルム バージョンエクス, Kaminari no Herumu: Bājon Ekusu) is the upgraded Original Vongola Lightning Ring. Talbot upgraded it with the Vongola Box Ring, Gyuudon, and Penalty. The Helmet has Gyuudon as its emblem in the front, and on the forehead of Gyuudon lies the Vongola Emblem which has a large "X". The helmet is also equipped with a set of horns on its sides, and the jaw of the Helmet is marked by an "X" with the lightning emblem engraved on its chin. Gyuudon can be summoned by using Thunder Set. When Lambo activates his Vongola Gear Cambio Forma, Gyuudon changes into armor and a set of horns. Unfortunately, the five year old Lambo can't fit into the helmet properly, although Gokudera noted that this was only because of all the junk that Lambo has got stored in his hair.