Durandal is a rapier, and is almost equal to Cavendish's height when he is sitting. Its sheath and hilt have a dark-light colored, vertical-striped pattern. The hilt is also adorned with several rings and graven flowers.
When Durandal is unsheathed, it seems to steadily shine.
Durandal is said to be made of very flexible iron, allowing it to withstand impacts that would otherwise crush normal swords. This was demonstrated when Cavendish held back Chinjao's headbutt technique, with Durandal only slightly bending from the sheer force of Chinjao's attack.
Biken: Blue Bird (美剣 青い鳥,Biken: Burū Bādo?, literally meaning "Beautiful Sword: Blue Bird"): Cavendish stabs his enemy directly with force. This attack is strong enough to hold Chinjao's strong headbutt which also creates a small shock-wave while clashing. In the Funimation dub, it is called Blade of Beauty: Blue Bird. This attack was first seen against Chinjao in Corrida Colosseum.The Blue Bird is a Belgian play.
Biken: Swan Lake (美剣 白鳥の湖,Biken: Suwan Reiku?, literally meaning "Beautiful Sword: Swan Lake"): Cavendish does a flip over his enemies and attacks them from above. This attack was first seen against Donquixote's thugs. In the Funimation dub, it is called Blade of Beauty: Swan Lake. Swan Lake is a Russian ballet.
Biken: Zan t-Exupéry (美剣 斬・星屑王子,Biken: Zan Tegujuperi?, literally meaning "Beautiful Sword: Slash: Stardust Prince"): Cavendish slashes the air in front of him which knocks his enemies away. This attack was first seen when Cavendish used it to carve a path spiraling up around the plateau on Dressrosa.Antoine de Saint-Exupéry was the author of the novel The Little Prince. The meaning of attack, the novel and Cavendish's epithet are puns, ending with prince. In the Funimation dub, it is called Blade of Beauty: Zan t-Exupéry.
Biken: Round Table (美剣 円卓,Biken: Raundo Tēburu?, literally meaning "Beautiful Sword: Round Table"): Cavendish slashes his enemy in circle formation while he is spinning. This attack was first seen against immortal skull toys after one of them bit Farul. The "Round Table" is King Arthur's famed table in the Arthurian legend, around which he and his knights congregate. The Round Table is also a collection of English essays. In the Funimation dub, it is called Blade of Beauty: Round Table.